Saunify Kaggeholm is a self-service sauna beside Lake Mälaren at Kaggeholm Castle on Ekerö, an island just outside Ekerö. Its glass front looks over the lake, and the sauna door opens towards the water. A swimming jetty is a few steps away, with the cold plunge less than ten metres from the sauna.

Book online for a shared session or a private booking. Sessions last 60 or 120 minutes, the sauna holds up to eight people and is heated to 80–90°C before you arrive. Opening hours are 06:00–23:00. Prices start at 149 kr per person (about $14.2, £11.2). Pay online by card, Swish or a Swedish wellness-allowance portal; a personal entry code is sent by email. There is no staff on site: enter the code at the digital lock at your booked time.

Bring a towel, swimwear and water; other essentials are on site. By public transport, take a bus to Kaggeholm slott stop, about 300 metres or a four-minute walk away. By car, drive to Kaggeholm Strandbistro, then walk down to the water. Visit Stockholm says the lake and park can be especially atmospheric on a cold evening, when mist rises from the water.