Archaeological investigations conducted in the mountainous territory of the ancient Lycian city of Tlos revealed significant information regarding the prehistoric past of the region. One of the most important discoveries is probably the Tavabaşı Cave, which has evidence for prehistoric rock art. Tavabaşı is composed two caves located very close one another, namely the upper cave and the lower cave. A group of figures painted in red have been documented on the weathered surface of the rock face above and to the left of the small entrance to the lower cave. These rock paintings are characterized by various geometric motifs, ornaments, unidentified signs and human figures. In terms of style, they strongly resemble rock paintings identified at numerous locations in the Latmos Mountains to the northwest. Previously, it was accepted that the Latmos examples were the only testimonies to rock art in western Anatolia. Tavabaşı presents new evidence for the southward expansion of this tradition. It is proposed that the paintings observed on the façade of the lower cave could be dated to the first half of the fifth millennium BC in the light of two radiocarbon dates from the trial trench conducted inside the lower cave. This dating is more-or-less in accordance with the date offered for rock paintings in the Latmos Mountains, which accepted to be from the late sixth and fifth millennia BC based on the stylistic comparison of figures with those observed on painted pottery from the Lake District.