Found during construction work in 1893, the 58 square metre mosaic floor quickly became one of the leading attractions of the health-resort city. Its hypocaust heating system is completely preserved. A walk through the understructure of the mosaic provides a view of the underside of the floor and reveals the principle and functionality of the Roman hypocaust system. The lively picture of the main mosaic depicts a scene in an amphitheatre. This is surrounded by a group of pictures alternating between gladiator and animal fights.

The Thraex (plural Thraeces, "Thracians") wore the same protective armour as the hoplomachi with a broad-rimmed helmet that enclosed the entire head, distinguished by a stylized griffin on the protome or front of the crest (the griffin was the companion of the avenging goddess Nemesis), a small round or square-shaped shield (parmula), and two thigh-length greaves. His weapon was the Thracian curved sword (sica or falx, c. 34 cm/13 in long). They were introduced as replacements for the Gauls after Gaul made peace with Rome. They commonly fought Myrmillones or Hoplomachi.