A trilithon, or trilith is a structure consisting of two large vertical stone posts supporting a third stone set horizontally across the top (lintel). It is commonly used in the context of megalithic monuments.
The word trilithon is derived from the Greek having three stones. The term also describes the groups of three stones in the Hunebed tombs of the Netherlands and the three massive stones forming part of the wall of the Roman Temple of Jupiter at Baalbek, Lebanon.
The location of the megalithic structures is atop of a hill in the region, known as Tel Baalbek. Numerous archaeological expeditions have gone to the site starting in the 19th century, primarily German and French groups, and research continued into the 20th century.
Each one of these stones is 19 meters long, 4.2 meters high, and 3.6 meters thick, and weighs around 800 tonnes. The supporting stone layer beneath features a number of stones which weigh an estimated 350 tonnes and are 11 meters wide.
Ancient Aliens / ABC Flash Point News 2022.