Often hotels with swimming pools will let non-guests purchase a pass to their pool but it can be pricey. Sometimes there are municipal swimming pools that do not make it to the guide books but which accept walk-in guests for a modest fee. I am seeking info on the indoor swimming options in the Tel Aviv area, Israel.
This page has a list of swimming pools in Tel Aviv, both in and outdoor. It also has links to their sites, and prices.
The pools that don't have a price on the page, also don't have a price on their site.
The pools that do have a price listed: