This place is AWESOME. My friend was visiting from Madrid and we wanted to have a very Swedish…read moreadventure so we went polar bear swimming in the lake in Feb! It was definitely an ADVENTURE, and very exhilarating! The place itself is cool, they have lots of little huts in the complex, a restaurant, a place to rent ice skates, and then a locker room with separate showers and saunas for men and women (nothing fancy, but clean enough!).
Basically, you arrive, change into your swimsuit (or nothing at all, as many people did!) hustle down to the water, hop in for a few seconds, and hustle back to the sauna and spend half an hour getting your body temp back up to normal :) And repeat.
My biggest piece of advice is BRING SANDALS! We didn't and our feet are suffering from painful frostnip now. Luckily some girls there were super nice and for our second dip, they lent us their flip flops for the icy walk down to the water. It made a HUGE difference.
A bus takes you right from Slussen to Hellasgarden (about a 20 min ride), and it's only 60kr entrance fee for many hours of entertainment- best deal in Stockholm!
Only drawback is the guy who is working at the cash register where you pay to enter is a real nightmare. But aside from him, it was sweet :)