A pyramid is a structure whose outer surfaces are triangular and converge to a single point at the top, making the shape roughly a pyramid in the geometric sense. The base of a pyramid can be trilateral, quadrilateral, or any polygon shape, meaning that a pyramid has at least three outer triangular surfaces (at least four faces including the base). The square pyramid, with square base and four triangular outer surfaces, is a common version.

A pyramid's design, with the majority of the weight closer to the ground, and with the pyramidion on top means that less material higher up on the pyramid will be pushing down from above. This distribution of weight allowed early civilizations to create stable monumental structures. More recently, it was shown that the common shape of the pyramids of antiquity, from Egypt to Central America, represents the dry-stone construction that requires minimum human work.

Pyramids have been built by civilizations in many parts of the world. For thousands of years, the largest structures on Earth were pyramids—first the Red Pyramid in the Dashur Necropolis and then the Great Pyramid of Khufu, both of Egypt, the latter is the only one of the Seven Wonders of the Ancient World still remaining. Khufu's Pyramid is built mainly of limestone (with large red granite blocks used in some interior chambers), and is considered an architectural masterpiece. It contains over 2,000,000 blocks ranging in weight from 2.5 tonnes (5,500 lb) to 15 tonnes (33,000 lb) and is built on a square base with sides measuring about 230 m (755 ft), covering 13 acres. Its four sides face the four cardinal points precisely and it has an angle of 52 degrees. The original height of the Pyramid was 146.5 m (488 ft), but today it is only 137 m (455 ft) high, the 9 m (33 ft) that is missing is due to the theft of the fine quality white Tura limestone covering, or casing stones, for construction in Cairo. It is still the tallest pyramid. The largest pyramid by volume is the Great Pyramid of Cholula, in the Mexican state of Puebla.

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    Bent Pyramid

    The Bent Pyramid is an ancient Egyptian pyramid located at the royal necropolis of Dahshur, approximately 40 kilometres south of Cairo, built under the Old Kingdom Pharaoh Sneferu (c. 2600 BC). A unique example of early pyramid development in Egypt, this was the second pyramid built by Sneferu.

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    Buried Pyramid (Pyramid of Sekhemkhet)

    The Buried Pyramid (also called the Pyramid of Sekhemkhet) is an unfinished step pyramid constructed ca. 2645 BC for Sekhemkhet Djoserty. This pharaoh was the second of the Third Dynasty of Ancient Egypt, which reigned over Egypt circa 2686–2613 BC and is usually placed at the beginning of the Old Kingdom of Egypt.

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    Great Pyramid of Giza (Pyramid of Khufu or the Pyramid of Cheops)

    The Great Pyramid of Giza (also known as the Pyramid of Khufu or the Pyramid of Cheops) is the oldest and largest of the three pyramids in the Giza pyramid complex bordering what is now El Giza, Egypt. It is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact.

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    Monks Mound, Cahokia

    Monks Mound is the largest Pre-Columbian earthwork in the Americas and the largest pyramid north of Mesoamerica. Located at the Cahokia Mounds UNESCO World Heritage Site near Collinsville, Illinois, the mound size was calculated in 1988 as about 100 feet (30 m) high, 955 feet (291 m) long including the access ramp at the southern end, and 775 feet (236 m) wide.

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    Northern Mazghuna Pyramid

    The Northern Mazghuna Pyramid is an ancient Egyptian royal tomb which was built during the 12th or 13th Dynasty in Mazghuna, 5 km south of Dahshur. The building remained unfinished and is still unknown which pharaoh was really intended to be buried here since no appropriate inscription has been found.

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    Pyramid G1-a, Pyramid of Hetepheres I

    G1-a is one of the subsidiary pyramids of the Giza East Field of the Giza Necropolis immediately to the eastern side of the Great Pyramid of Giza, built during the Fourth dynasty of Egypt.

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    Pyramid G1-b, Pyramid of Meritites I

    G1-b is one of the subsidiary pyramids of the Giza East Field of the Giza Necropolis immediately to the eastern side of the Great Pyramid of Giza, built during the Fourth dynasty of Egypt.

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    Pyramid G1-c, Pyramid of Henutsen

    G1-c is one of the subsidiary pyramids of the Giza East Field of the Giza Necropolis immediately to the eastern side of the Great Pyramid of Giza, built during the Fourth dynasty of Egypt.

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    Pyramid of Amenemhat III (Black Pyramid)

    The Black Pyramid was built by King Amenemhat III during the Middle Kingdom of Egypt (2055-1650 BC). It is one of the five remaining pyramids of the original eleven pyramids at Dahshur in Egypt. Originally named Amenemhet is Mighty, the pyramid earned the name "Black Pyramid" for its dark, decaying appearance as a rubble mound.

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    Pyramid of Amenemhet I

    The Pyramid of Amenemhet I is an Egyptian burial structure built at Lisht by the founder of Egypt's 12th dynasty, Amenemhet I. This structure returned to the approximate size and form of old kingdom Pyramids.

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    Pyramid of Ameny Qemau

    The Pyramid of Ameny Qemau is located in southern Dahshur. It was constructed c. 1790 BC for Ameny Qemau, the 5th king of the 13th Dynasty during the Second Intermediate Period. The stone constituting its upper structure has been entirely robbed but the damaged substructures remain.

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    Pyramid of Djedefre

    The Pyramid of Djedefre consists today mostly of ruins located at Abu Rawash in Egypt. It is Egypt's most northerly pyramid, and is believed to be built by Djedefre, son and successor to king Khufu. Though some Egyptologists in the last few decades have suggested otherwise, recent excavations at Abu Roash carried out by Dr. Michael Baud of the Louvre Museum in Paris suggest the pyramid was in fact never finished.

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    Pyramid of Djedkare-Isesi

    The pyramid of Egyptian pharaoh Djedkare-Isesi was built at South Saqqara in the fifth dynasty. The translation of its ancient Egyptian name is Beautiful is Djedkare.

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    Pyramid of Djoser

    The Pyramid of Djoser (or Zoser), or step pyramid is an archeological remain in the Saqqara necropolis, Egypt, northwest of the city of Memphis. It was built during the 27th century BC for the burial of Pharaoh Djoser by Imhotep, his vizier. It is the central feature of a vast mortuary complex in an enormous courtyard surrounded by ceremonial structures and decoration.

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    Pyramid of Khaba

    In the King-list Khaba is called Hudjefa. His pyramid is the so-called Layer Pyramid at Zawiyet el-Aryan. The pyramid is a step pyramid in the early stages of construction. The superstructure is typical of 3rd dynasty masonry, consisting of 14 accretions, leaning inward against a central core.

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    Pyramid of Khafre

    The Pyramid of Khafre or of Chephren is the second-tallest and second-largest of the Ancient Egyptian Pyramids of Giza and the tomb of the Fourth-Dynasty pharaoh Khafre (Chefren), who ruled from c. 2558 to 2532 BC.

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    Pyramid of Khendjer

    The Pyramid of Khendjer was a pyramid built for the burial of the 13th dynasty pharaoh Khendjer, who ruled Egypt c. 1760 BC during the Second Intermediate Period. The pyramid, which is part of larger complex comprising a morturary temple, a chapel, two enclosure walls and a subsidiary pyramid, originally stood around 37 m (121 ft) high and is now completely ruined.

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    Pyramid of Khentkaus I

    Pyramid of Khentkaus I. The pyramid was originally described in the 19th century as an unfinished pyramid and it had been conjectured that it belonged to King Shepseskaf.

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    Pyramid of Khentkaus II

    Pyramid of Khentkaus II. The pyramid had initially been excavated in 1906 by Borchardt. The structure was then thought to be a double mastaba and was not excavated very thoroughly. Seventy years later the Czech Institute conducted a thorough excavation of the site.

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    Pyramid of Menkaure

    The Pyramid of Menkaure, located on the Giza Plateau in the southwestern outskirts of Cairo, Egypt, is the smallest of the three main Pyramids of Giza. It is thought to have been built to serve as the tomb of the fourth dynasty Egyptian Pharaoh Menkaure.

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    Pyramid of Merenre

    The burial pyramid of Pharaoh Merenre was constructed during the Egyptian sixth dynasty at Saqqara 450 metres (1,480 ft) to the south-west of the pyramid of Pepi I and a similar distance to the pyramid of Djedkare.

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    Pyramid of Neferefre

    The Pyramid of Neferefre, also known as the Pyramid of Raneferef, is an unfinished Egyptian pyramid from the 5th Dynasty, located in the necropolis of Abusir, Egypt. After the early death of Pharaoh Neferefre, the unfinished building was reconstructed into a geometric mastaba, becoming the burial place of the deceased king.