STF Långholmen Hostel

STF Långholmen Hostel occupies the entire former Långholmen Prison, a Swedish state prison built in the 1840s and closed in 1975. The building was converted into a hostel in 1989 and runs as part of the STF (Swedish Tourist Association) network. Långholmen is a small island on the west side of Södermalm — you walk across a short pedestrian bridge from Hornstull, and the island is otherwise given over to a public park, a small swimming beach, and the prison-turned-museum next door to the hostel.

The rooms are literally converted cells. Most have been knocked together into larger dorms (4, 6 beds) but the original cell structure shows: thick walls, narrow windows, heavy doors. Many rooms now include a private bathroom (rare at this price in Stockholm). The dorms are quiet because the walls are 30cm of stone. It's the best sleep quality of any budget hostel in Stockholm by a margin.

On-site is a full shared kitchen, a breakfast restaurant (paid, genuinely good for STF standards), and a rooftop terrace bar in summer. There's no nightclub scene on the island itself — it's a 5-minute walk back over the bridge to Hornstull's bars (Debaser Strand, Rival, the SoFo adjacent drinking circuit).

The main trade-off is transit. Hornstull metro is a 12-minute walk (red line to T-Centralen, 8 minutes). T-Centralen is a 20-minute total commute. Buses 4 and 66 serve the island directly — bus 4 runs every 5 minutes and connects to Södermalm and Kungsholmen. If you're on a short Stockholm visit and want the city-centre hostel, this isn't it. If you want 3+ nights of actual sleep, Södermalm proximity, and a 'stayed in a prison' story to bring home, STF Långholmen is the play. The prison museum next door ('Långholmens Fängelsemuseum') is a free add-on to your booking.