grean, alaine is 100% correct.
Spa Castle (in carrollton
http://tx.spacastleusa.com/) and King Spa (in dallas
http://www.kingspa.com/dallas/) are legit, non-sexual, non-promiscuous facilities w/ dry & steam saunas, HOT tubs (like 100+ degrees), cold plunge pools, hot rooms (hot rocks, bricks, walls, pipes under floors, etc), massage therapy services, a mini-"water park" (pools, slides, poolside bars, etc.), and food (mostly asian, but great smoothie like drinks at King Spa).
spa castle is $35 during weekdays and looks snazzier (havent been there). has a hotel next door (where one
could go to get their jollies and/or delites)
king spa is $45 and is older but updated (went 3-4 yrs ago, but havent been recently). 10 admits for 250$.
they are alot of fun and relaxing.