Part of something bigger
The sauna is one piece of Corralea, an outdoor centre beside Lough Macnean that also runs self-catering cottages and other activities. That is why the sauna often turns up bundled into an overnight stay rather than sold purely as a standalone hour.
It also explains the format. Two hours of exclusive lakeside use is a different proposition from a £20 seat on a beach. This is the one you book when you want the water, the woods and the quiet, and you are willing to drive west to get them.