It is warmed by the sun. The Mineral pool was damaged during a hurricane a few years ago and was redone and is a new pool. The depth was changed from 9' to no more then 5' and it has a new patio around it.
It has some soothing minerals put in daily
At one point in the 60's and 70's it was the main pool @ Sans Souci
We were there last year, the water is a bit cold ,but not too bad
The is a sign by the pool as to what minerals are in the pool, Sorry can't remember what they were, maybe some one has a Pix of that sign?
From the Web Site
"Our mineral waters are the source from which our popularity first sprang forth. As far back as the 1700s, the mineral springs on the Couples Sans Souci property have been cited in Jamaican history books as excellent for maintaining health and renewing romantic energy. For generations, people from nearby villages would congregate on Sundays, lining up for the entire day to take their dip into the mineral spring with the curious curative power"