From the Room of the Nereids, through a wide access, you enter an environment with floor in “opus sectile” that is composed of refined marble inlays. The walls, originally covered with marbles and colored plasters, gave the room an elegant appearance. On the southern side there is a large circular basin with marble slabs and a monochrome mosaic on the floor. The three marble window sills on the back wall suggest the presence of niches or windows. Another tank, much smaller, is visible in the south-western corner, its drainage channel has cut the floor of marble slabs, subsequently arranged with recovered material. The Room of the Nereids also serves as access to the three rooms of the “calidarium” which have tubules on the walls and floors made of recovered marble. The first two have an apsidal rectangular shape, while the third, square in shape, has two heated semicircular tanks.