If you want to go to Millesgärden, an outdoor museum in Stockholm from Carles Mille’s sculptor, you’ll have to catch the train 21 from Ropsten metro station. Don’t make the same mistake as me. At Ropsten, I had a look at the notice board indicating next buses’ departures. As there were only buses, I thought I had made a mistake while copying the indication From SL’s website. I was waiting for some info, but as there was no indication for the 21, I asked at the ticket office.
The guy told me that it was a train and that I had to go upstairs to catch it. I have been walking around about 10 minutes to find it, and of course I missed the train. Luckily next one was only 20 minutes later. So just follow Lidingöbanan when you get out of the metro and you’ll be fine! The park is not that big, so in less than 2 hours you’ll be done. If you are not spending a week in Stockholm, I won’t recommend you to go and visit it, as you’re losing time to get there when there are so many things to see in Stockholm.