A tholos is a circular building or tomb that was commonly used in ancient Greek architecture. These structures often feature a domed roof and are typically made of stone. Tholoi were used for various purposes, including burial sites and ceremonial spaces, and are notable for their unique design and construction techniques. One of the most famous examples of a tholos is the Tholos of Delphi, which served as a treasury for the Delphic Oracle. Tholoi can also be found in other ancient cultures, such as the Minoans on the island of Crete, showcasing their significance in historical architecture.