One of the 20+ different pools and other water features scattered around the site.
Set in a 12 metre deep tufa cave, 4m high, there's a warm water relaxation pool, as well as
a sauna cave, cold water well and a deep thermal plunge pool.
Outside there's a row if seats under water spouts, with three jets for neck and back massage.
For more about the individual pools... http://www.negombo.it/pdf/negombo-filo-di-arianna-en.pdf