A grand and imposing octagonal swimming pool dominates the area, which was used as the locker room where the users could rest before or after their bath.
The most important part of the social relations among the users of the Baths used to take place in this area which is also the most spacious part of the installations. Around and over the swimming pool a number of columns are elevated and they are topped with a dome.
In the past, the pool was filled with rain water taken from the roof. The users were able to refresh themselves soaking their arms and face but they could not swim in it. The capitals of the roof lantern (day lighting cupola) present a unique sculptural decoration based on animal and architectural themes and also designs taken from the nature.
On the wall of the North side, we can find a massive bench, from the east to the west, elevated by six solid sections of a barrel vault. It was used to keep all the personal belongings and in order for the users to sit comfortably on it. From there you can get into the frigidario..