The large bath in Tlos and the small bath next to it form a bathing and sports complex and thus a spatial unit.

The larger bath has a floor plan with three adjacent rooms that followed the Roman bathing sequence: apodyterium, frigidarium, tepidarium and caldarium. The frigidarium was equipped with an apse whose arcade windows offered a magnificent view of the Xanthos valley. The rooms were covered with barrel vaults, with the vault of the central room subdivided in later times.

The smaller of the two baths had two bathrooms and an apodyterium (changing room) at right angles to it from where one could reach the northern Palästra. The barrel vaults of the halls are still preserved.