Kvika

Technically, this is not just a hot pool, it is a piece of art, a statue! Made by Ólöf Nordal. It is not big enough to bath in there (unless you are a snake man), but it is great for foot baths.

How to Find Kvika:

Kvika geothermal foot pool is located in Reykjavík in walking distance from the city center, so if your foots are tired, you can let them relax right here after the walk. There is plenty of room to park your car too.
GPS coordinates of Kvika: 64.162390, -22.008373 Take me there!

Photos of the Kvika geothermal art pool: