Between the 1st century B.C. and 3rd century A.D., the Italian coastal town of Baia was a hot spot for vacationing Roman aristocracy and imperial families. Now, the once bustling city is mostly submerged, including what was once a spa crafted with mosaic and marble floors.

The spa, known as Terme del Lacus, opened to the public in the summer of 2020, according to Campi Flegrei, the archaeological park that is home to the spa. Recently though, archaeologists noticed something strange beneath the sand, Parco Archeologico Campi Flegrei said in a Facebook post. Underneath the sand they discovered a new, vibrant mosaic.