The Great Pyramid seen through the Guardian of Forever
The Pyramids seen in the resetting time stream
Pyramids were built by numerous Human Earth cultures as monuments, burial sites, and places of worship. They were part of the city designed by Kukulkan. All of the ancient human cultures influenced by Kukulkan built some type of pyramid, although none of them did it in the perfect way that he had planned. (TAS: "How Sharper Than a Serpent's Tooth")
The series of monumental burial chambers built for Egyptian kings of Earth, are among the oldest known, dating from the 27th Century BC. The Great Pyramid of Giza was the largest of the pyramids, and one of Earth's most notable landmarks. It had been observed by anthropolgists, following proper time travel protocols, since 2769. Daniels showed temporal observers watching the pyramid's construction to Captain Archer in the temporal observatory. (ENT: "Cold Front")
After Archer restored a damaged timeline, the Pyramids could be seen in the timestream as the timeline realigned itself. (ENT: "Storm Front, Part II")
The Great Pyramid was also among the images displayed by the Guardian of Forever. (TOS: "The City on the Edge of Forever")
Another prominent pyramid-shaped structure on Earth (albeit of less historical relevance) is the Transamerica Pyramid.
Pyramid-like structures also dominated the Ventax II skyline. (TNG: "Devil's Due")
The dice used by the Wadi for their game chula were pyramidic. (DS9: "Move Along Home")