The Bevy Mausoleum is an ancient structure located in Turkey, often overlooked despite its precise and unexplained architecture. Academia believes it to be a tomb from the Hellenistic era, built around the 3rd century BC as a burial site for Antiochus 2 Theos, a ruler of the Salid dynasty. However, the advanced precision techniques involved in its original build suggest a lost knowledge and civilization. The chamber and sarcophagus of the mausoleum were precisely carved from solid rock, with a square plan of 29 meters in length and 10 meters in height. The rock was then covered with marble slabs traced to a quarry near Ephesus, requiring up to 2,500 cubic meters of marble to complete the decorations. A second level, surrounded by 28 columns, has since turned to dust. The original builder and purpose of the mausoleum remain unknown, but it is believed to have been the burial site of an important person from a much earlier time than Academia's suggested construction date.

In Texas, an ancient wall was unearthed in 1852 that is still heavily debated today. Conservative estimates place its creation 100,000 years ago, but some believe it to be an antediluvian relic left by a lost civilization 200–400,000 years ago. Dr. John Gman of the University of Texas at Dallas tested the rocks as part of a History Channel documentary, claiming that they formed where they lay and were all magnetized in the same way, suggesting a natural origin. However, geologist James Shelton and Harvard's architect John Lindsay have focused on its unique design features, including archways, lintel portals, square doorways, and window openings, which suggest artificial creation and functionality for humans. The depth and height of the wall are also impressive, with an excavation reaching 40 feet deep without finding the bottom. Megalithic stones were discovered at considerable depth and weight. The wall's original builders and purpose remain a mystery.