Maximare

Fantastic sauna/swimming complex. I think Maximare is probably the best of its kind in the area.
They have an olympic sized indoor swimming pool, wave pool, and water slides.
There are about 7 different types of saunas in their outdoor sauna area.
Everything is spotlessly clean.
It's easy to spend all day here.
They also have a restaurant and cafe so you can rehydrate yourself after sweating for hours.


If you're ever in Hamm (unlikely, I know), check it out.

I use the 50m sports pool for 3,50 per 90 minutes. If u want to go to the other areas, pay 9,- for 3h. Opening hours are practical, it seems to have no match of a pool in the area. Price could be lower, the WC area is too small, the well-functioning warm showers are a few steps away from the locker rooms.
I haven't found a schedule for the frequent teaching groups, so it seems unclear when u can expect more or less pool space available for swimming.