In addition to its hygienic function, baths (balneae) were a place to socialize. Thermal installations, which were set with all types of luxury, were built to satisfy earthly pleasures in the same way as libraries would fulfil the  mind.
Several rooms made up the baths in Torre Llauder:

Apodyterium (changing-room)
Frigidarium (cold-water baths)
Tepidarium (warm baths)
Caldarium (hot-water baths)
Walls of the cold-water pool were covered with red opus signinum to prevent water  leaking. The lower steps of the flight of steps leading into the pool were covered with marble.
The floor of the cold-water baths room (frigidarium) was paved with slate slabs and framed by a white marble edging. A step, also covered with slate slabs, gave access to the pool, which had an apse on its northern side.
From the frigidarium there was access into the room of hot-water baths (caldarium) by going through a warm room (tepidarium).
Both the tepidarium and the caldarium were  heated by means of an under-floor heating system known as hypocaust. A top floor (suspensura) was supported on tile stacks (pilae) to form an area through which hot gases drawn from the furnace (praefurnium) circulated.
Hot water for a small pool (alveus) was heated in a bronze or lead  boiler placed directly on top of the  furnace. As with the cold-water pool, this pool was waterproofed by a covering of red opus signinum.
A small room next to the furnace was most probably used for storing firewood.
[Map]   [Atrium]   [Aula I]   [Aula II-III]   [Peristylum]   [Balneae]   [Latrinae]