Upvote:6
When you use a search website for hotels, there is usually many filters for the search criteria. One of them will be "Amenities" or "Property Facilities" or "Fun Things To Do".
For instance, on Agoda.com you can search for hotels and filter "Property Facitilies" by "Spa/Sauna".
For instance, on Booking.com you can search for hotels and filter by "Fun Things To Do" and sauna is one of them.
On Kayak.com, they use "Amenities" to filter on "spa".
Keep in mind, saunas are not easy to find in warmer climates. Most places use the term "spa" and will have sauna features in their hotel spa. I hope that helps.