As of November 2008, sources cite either 118 or 138 as the number of identified Egyptian pyramids.  Most were built as tombs for the country's pharaohs and their consorts during the Old and Middle Kingdom periods.  
The earliest known Egyptian pyramids are found at Saqqara , northwest of Memphis . The earliest among these is the Pyramid of Djoser (constructed 2630 BCâ€“2611 BC) which was built during the third dynasty . This pyramid and its surrounding complex were designed by the architect Imhotep , and are generally considered to be the world's oldest monumental structures constructed of dressed masonry .
The most famous Egyptian pyramids are those found at Giza , on the outskirts of Cairo . Several of the Giza pyramids are counted among the largest structures ever built.  The Pyramid of Khufu at Giza is the largest Egyptian pyramid. It is the only one of the Seven Wonders of the Ancient World still in existence.
The second historically-documented Egyptian pyramid is attributed to the architect Imhotep , who planned what Egyptologists believe to be a tomb for the pharaoh Djoser . Imhotep is credited with being the first to conceive the notion of stacking mastabas on top of each other, creating an edifice composed of a number of "steps" that decreased in size towards its apex. The result was the Pyramid of Djoser , which was designed to serve as a gigantic stairway by which the soul of the deceased pharaoh could ascend to the heavens. Such was the importance of Imhotep's achievement that he was deified by later Egyptians.
The most prolific pyramid-building phase coincided with the greatest degree of absolutist rule. It was during this time that the most famous pyramids, the Giza pyramid complex , were built. Over time, as authority became less centralized, the ability and willingness to harness the resources required for construction on a massive scale decreased, and later pyramids were smaller, less well-built and often hastily constructed.
Long after the end of Egypt's own pyramid-building period, a burst of pyramid-building occurred in what is present-day Sudan , after much of Egypt came under the rule of the kings of Napata . While Napatan rule was brief, ending in 661 BC , Egyptian culture made an indelible impression, and during the later Kingdom of MeroÃ« (approximately in the period between 300 BCE â€“ 300 CE), this flowered into a full-blown pyramid-building revival , which saw more than two hundred Egyptian-inspired indigenous royal pyramid-tombs constructed in the vicinity of the kingdom's capital cities.
The shape of Egyptian pyramids is thought to represent the primordial mound from which the Egyptians believed the earth was created. The shape of a pyramid is thought to be representative of the descending rays of the sun, and most pyramids were faced with polished, highly reflective white limestone, in order to give them a brilliant appearance when viewed from a distance. Pyramids were often also named in ways that referred to solar luminescence. For example, the formal name of the Bent Pyramid at Dahshur was The Southern Shining Pyramid , and that of Senwosret at el-Lahun was Senwosret is Shining .
While it is generally agreed that pyramids were burial monuments, there is continued disagreement on the particular theological principles that might have given rise to them. One suggestion is that they were designed as a type of "resurrection machine." 
The Egyptians believed the dark area of the night sky around which the stars appear to revolve was the physical gateway into the heavens. One of the narrow shafts that extend from the main burial chamber through the entire body of the Great Pyramid points directly towards the center of this part of the sky. This suggests the pyramid may have been designed to serve as a means to magically launch the deceased pharaoh's soul directly into the abode of the gods. 
All Egyptian pyramids were built on the west bank of the Nile, which, as the site of the setting sun , was associated with the realm of the dead in Egyptian mythology.
Number and location of pyramids
In 1842, Karl Richard Lepsius produced the first modern list of pyramids â€“ see Lepsius list of pyramids â€“ in which he counted 67. A great many more have since been discovered. As of November 2008, 118 Egyptian pyramids have been identified. 
The location of Pyramid 29, which Lepsius called the "Headless Pyramid", was lost for a second time when the structure was buried by desert sands subsequent to Lepsius' survey. It was found again only during an archaeological dig conducted in 2008.
Many pyramids are in a poor state of preservation or buried by desert sands. If visible at all, they may appear as little more than mounds of rubble. As a consequence, archaeologists are continuing to identify and study previously unknown pyramid structures.
The most recent pyramid to be discovered was that of Sesheshet at Saqqara , mother of the Sixth Dynasty pharaoh Teti . The discovery was announced by Zahi Hawass , Secretary General of the Egyptian Supreme Council of Antiquities , on 11 November 2008.
All of Egypt's pyramids, except the small Third Dynasty pyramid of Zawyet el-Amwat (or Zawyet el-Mayitin), are sited on the west bank of the Nile , and most are grouped together in a number of pyramid fields. The most important of these are listed geographically, from north to south, below.
Abu Rawash is the site of Egypt's most northerly pyramid (other than the ruins of Lepsius pyramid number one)  â€” the mostly ruined Pyramid of Djedefre , son and successor of Khufu . Originally it was thought that this pyramid had never been completed, but the current archaeological consensus is that not only was it completed, but that it was originally about the same size as the Pyramid of Menkaure , which would have placed it among the half-dozen or so largest pyramids in Egypt.
Its location adjacent to a major crossroads made it an easy source of stone. Quarrying â€“ which began in Roman times â€“ has left little apart from about 15 courses of stone superimposed upon the natural hillock that formed part of the pyramid's core. A small adjacent satellite pyramid is in a better state of preservation.
Giza is the location of the Pyramid of Khufu (also known as the "Great Pyramid" and the "Pyramid of Cheops"); the somewhat smaller Pyramid of Khafre (or Kephren); the relatively modest-sized Pyramid of Menkaure (or Mykerinus), along with a number of smaller satellite edifices known as "Queen's pyramids"; and the Great Sphinx of Giza .
Of the three, only Khafre's pyramid retains part of its original polished limestone casing, near its apex. This pyramid appears larger than the adjacent Khufu pyramid by virtue of its more elevated location, and the steeper angle of inclination of its construction â€“ it is, in fact, smaller in both height and volume.
The Giza pyramid complex has been a popular tourist destination since antiquity, and was popularized in Hellenistic times when the Great Pyramid was listed by Antipater of Sidon as one of the Seven Wonders of the Ancient World . Today it is the only one of those wonders still in existence.
This site, halfway between Giza and Abu Sir, is the location for two unfinished Old Kingdom pyramids. The northern structure's owner is believed to be pharaoh Nebka , while the southern structure, known as the Layer Pyramid , may be attributable to the Third Dynasty pharaoh Khaba , a close successor of Sekhemkhet . If this attribution is correct, Khaba's short reign could explain the seemingly unfinished state of this step pyramid. Today it stands around 17Â m (56Â ft) high; had it been completed, it is likely to have exceeded 40Â m (130Â ft).
There are a total of fourteen pyramids at this site, which served as the main royal necropolis during the Fifth Dynasty. The quality of construction of the Abu Sir pyramids is inferior to those of the Fourth Dynasty â€“ perhaps signaling a decrease in royal power or a less vibrant economy. They are smaller than their predecessors, and are built of low-quality local limestone.
The three major pyramids are those of Niuserre, which is also the best preserved, Neferirkare Kakai and Sahure . The site is also home to the incomplete Pyramid of Neferefre . Most of the major pyramids at Abu Sir were built similar construction techniques, comprising a rubble core surrounded by steps of mud bricks with a limestone outer casing. The largest of these 5th-Dynasty pyramids, the Pyramid of Neferirkare Kakai, is believed to have been built originally as a step pyramid some 70Â m (230Â ft) high and then later transformed into a "true" pyramid by having its steps filled in with loose masonry.
Major pyramids located here include the Pyramid of Djoser â€“ generally identified as the world's oldest substantial monumental structure to be built of dressed stone â€“ the Pyramid of Userkaf , the Pyramid of Teti and the Pyramid of Merikare , dating to the First Intermediate Period of Egypt . Also at Saqqara is the Pyramid of Unas , which retains a pyramid causeway that is one of the best-preserved in Egypt. Together with the pyramid of Userkaf, this pyramid was the subject of one of the earliest known restoration attempts, conducted by Khaemweset , a son of Ramesses II . Saqqara is also the location of the incomplete step pyramid of Djoser's successor Sekhemkhet known as the Buried Pyramid . Archaeologists believe that had this pyramid been completed, it would have been larger than Djoser's.
South of the main pyramid field at Saqqara is a second collection of later, smaller pyramids, including those of Pepi I, Isesi, Merenre, Pepi II and Ibi . Most of these are in a poor state of preservation.
The Fourth Dynasty pharaoh Shepseskaf either did not share an interest in, or have the capacity to undertake pyramid construction like his predecessors. His tomb, which is also sited at south Saqqara, was instead built as an unusually large mastaba and offering temple complex. It is commonly known as the Mastabat al-Firâ€™aun .
A previously unknown pyramid was discovered at north Saqqara in late 2008. Believed to be the tomb of Teti's mother, it currently stands approximately 5Â m (16Â ft) high, although the original height was closer to 14Â m (46Â ft).
This area is arguably the most important pyramid field in Egypt outside Giza and Saqqara, although until 1996 the site was inaccessible due to its location within a military base, and was relatively unknown outside archaeological circles.
The southern Pyramid of Sneferu , commonly known as the Bent Pyramid , is believed to be the first Egyptian pyramid intended by its builders to be a "true" smooth-sided pyramid from the outset; the earlier pyramid at Meidum had smooth sides in its finished state â€“ but it was conceived and built as a step pyramid, before having its steps filled in and concealed beneath a smooth outer casing of dressed stone.
As a true smooth-sided structure, the Bent Pyramid was only a partial success â€“ albeit a unique, visually imposing one; it is also the only major Egyptian pyramid to retain a significant proportion of its original smooth outer limestone casing intact. As such it serves as the best contemporary example of how the ancient Egyptians intended their pyramids to look.
Several kilometeres to the north of the Bent Pyramid is the last â€“ and most successful â€“ of the three pyramids constructed during the reign of Sneferu; the Red Pyramid is the world's first successfully completed smooth-sided pyramid. The structure is also the third largest pyramid in Egypt â€“ after the pyramids of Khufu and Khafra at Giza.
Also at Dahshur is the pyramid known as the Pyramid of Amenemhat III , as well as a number of small, mostly ruined subsidiary pyramids.
Two major pyramids are known to have been built at Lisht â€“ those of Amenemhat I and his son, Senusret I . The latter is surrounded by the ruins of ten smaller subsidiary pyramids. One of these subsidiary pyramids is known to be that of Amenemhat's cousin, Khaba II. The site which is in the vicinity of the oasis of the Faiyum , midway between Dahshur and Meidum , and about 100 kilometres south of Cairo , is believed to be in the vicinity of the ancient city of Itjtawy (the precise location of which remains unknown), which served as the capital of Egypt during the Twelfth Dynasty .
The pyramid at Meidum is one of three constructed during the reign of Sneferu , and is believed by some to have been started by that pharaoh's father and predecessor, Huni . However, that attribution is uncertain, as no record of Huni's name has been found at the site.
It was constructed as a step pyramid, and then later converted into the first "true" smooth-sided pyramid when the steps were filled in, and an outer casing added.
The pyramid suffered several catastrophic collapses in ancient and medieval times; medieval Arab writers described it as having seven steps â€“ although today only the three uppermost of these remain, giving the structure its odd, tower-like appearance. The hill on which the pyramid is situated is not a natural landscape feature â€“ it is the small mountain of debris created when the lower courses and outer casing of the pyramid gave way.
Amenemhat III was the last powerful ruler of the Twelfth Dynasty, and the pyramid he built at Hawarra, near the Faiyum, is believed to post-date the so-called "Black Pyramid" built by the same ruler at Dahshur . It is the Hawarra pyramid that is believed to have been Amenemhet's final resting place.
The pyramid of Senusret II at el-Lahun is the southernmost royal-tomb pyramid structure in Egypt. Its builders reduced the amount of work necessary to construct it by ingeniously using as its foundation and core a 12-meter-high natural limestone hill.
Piye, the first ruler of the Egyptian 25th dynasty, built a pyramid at El-Kurru. He was the first Egyptian pharaoh to be buried in a pyramid in centuries.
Taharqa, a legitimate ruler and Pharaoh of Egypt, built his pyramid at Nuri. It was the largest in the area (North Sudan).
The following table lays out the chronology of the construction of most of the major pyramids mentioned here. Each pyramid is identified through the pharaoh who ordered it built, his approximate reign, and its location.
|Pyramid / Pharaoh||Reign||Field|
|Djoser||c. 2670 BC||Saqqara|
|Sneferu||c. 2612â€“2589 BC||Dashur|
|Sneferu||c. 2612â€“2589 BC||Meidum|
|Khufu||c. 2589â€“2566 BC||Giza|
|Djedefre||c. 2566â€“2558 BC||Abu Rawash|
|Khafre||c. 2558â€“2532 BC||Giza|
|Menkaure||c. 2532â€“2504 BC||Giza|
|Userkaf||c. 2494â€“2487 BC||Saqqara|
|Sahure||c. 2487â€“2477 BC||Abu Sir|
|Neferirkare Kakai||c. 2477â€“2467 BC||Abu Sir|
|Nyuserre Ini||c. 2416â€“2392 BC||Abu Sir|
|Amenemhat I||c. 1991â€“1962 BC||Lisht|
|Senusret I||c. 1971â€“1926 BC||Lisht|
|Senusret II||c. 1897â€“1878 BC||el-Lahun|
|Amenemhat III||c. 1860â€“1814 BC||Hawara|
|Khendjer||c. 1764â€“1759 BC||Saqqara|
|Piye||c. 721 BC||El-Kurru|
|Taharqa||c. 664 BC||Nuri|
Constructing the pyramids involved moving huge quantities of stone. The quarried blocks were likely transported to the construction site by wooden sleds, with sand in front of the sled wetted to reduce friction . Droplets of water created bridges between the grains of sand, helping them stick together. 
- Egyptian pyramid construction techniques
- Al Ahram , Arabic for "the pyramids", name of Egyptian newspaper