The statement that the Romans were aware of the Vrnjci mineral waters and that they were using them was already issued by Felix Kanic, in his travel-record “Examination of the Roman Monuments in the Kingdom of Serbia”, written at the end of the 19th century. He says that the Vrnjci thermae were south of the castrum in the village Grachac, but during the work of seizing and regulation of waters, in the 19th century, there were no visible remnants on the ground, or they couldn’t be recognized by the workers. The traces of the Roman period were discovered accidentally, during the seizing and regulation of hot springs in spring 1924. At the depth of 2.4m a vertical, regularly sculptured rock was discovered, out of whose opening hot mineral water was flowing.

Near the hot spring in the rock, 200 Roman coins were discovered, belonging to the period from August to Valentinian. Next to the Roman spring, on the approximately same depth, remnants of the first known bathing pool were discovered. The pool is filled with hot mineral water from a separate spring engraved in a rock, like from a small well. 60 Roman coins were discovered in the pool, dating back from the second half of the 4th century, one ring and one key.