The tholos at Epidaurus was built in approximately 360 CE. Built by an architect named Polycleitus, the tholos has been referred to as “the finest of all tholoi according to ancient opinion” (Lawrence 1957). The tholos at Epidaurus has been identified as a thymela, or place of sacrifice, based on the inscription found, which has a record of the money spent and received on the building, and was dedicated to the hero-god Asklepios. Construction of the tholos was done over a period of twenty years, as funding permitted. Because of funding issues, the building was built primarily of limestone, except where exact carvings required marble.
Polycleitus’ tholos is 21.82 meters in diameter. The entrance used to have three steps with a sloping causeway. The building boasts 26 columns of the pteron, their placement farther apart that was made possible by a flatter arc. On top of the columns was a freize with carved metopes that featured large rosettes in the center and a marble gutter which was adorned with acanthus leaves. The antefixes, which would have edged the tiled roof, were shaped like palmettes. The wall of the cella was covered in white stucco, which is recorded as being painted on by the artist Pausius (Lawrence1957). Inside the cella stood fourteen columns of the Corinthian order topped with carvings of foliage so delicate it could not withstand the collapse of the buildings. However, a spare capital, which was found buried under the floor of the tholos, remains intact. A pair of windows on either side of the doorway allowed light into the cella, and there may have been additional windows higher in the wall. The cella was paved primarily with black and white stone slabs, alternating in a pattern, but was interrupted in the center by access to the labyrinthine basement.
Like the tholos at Delphi, there is reason to believe that there was a separate roof over the cella. There are remains of the acroterion which is believed to have been the culmination of this second, conical roof. These remaining slabs feature coffers which still hold traces of paintings.
The Philippeum tholos, located at Olympia, was built around 335 BCE, primarily to hold statues of the Macedonian royal family. The pteron of the structure was Ionic but features a row of dentils above the frieze, a combination of two previously incompatible architectural elements. The inner wall of the cella featured engaged Corinthian half columns, which would have performed no structural or weight-bearing purpose. This is odd, considering the interior cella columns in the tholos at Delphi, as well as Epidaurus would have presumably supported a separation between open and covered areas of the building. At the tholos at Olympia, the roof of the cella is thought to have culminated in a bronze poppy head placed there to cover the ends of the beams, according to Pausanias.