Centralbadet in Stockholm
opens 6 am, 110 SEK, towels extra. It's beautiful to look at, but not great for swimming. Kinda like asking for a nice hearty breakfast, and getting a Viennese pastry shop.
The rule is counter-clockwise swimming, but each swimmer interprets that differently, and at their own pace. It ends up like driving in heavy traffic, where you spend most of your time calculating how to avoid hitting the person ahead of you.