Sundhöllin

Sundhöllin opened in 1937 as the first purpose-built indoor pool in Reykjavík. It was one of the first buildings in the city to use geothermal water, piped 3 km from Laugardalur. The work was meant to finish in 1930, but the Great Depression stalled it.

The building itself is the reason to come: a minimalist white exterior close to Art Deco, tall narrow windows, arches along the south side of the pool hall, tiled changing rooms. The main pool is 25 by 10 metres and drops from 0.9 to 4 metres. In 2017 an outdoor section was added, with a shallower 25 metre four-lane pool, a playpool, a large hot tub with massage spouts, a cold tub at around 10 °C and a sauna.

Swimming became compulsory for Icelandic schoolchildren in 1927, and Sundhöllin became the city's main teaching pool. It still works as a neighbourhood pool rather than a spa.

• Shower without a swimsuit. A naked shower in an open cubicle is required before you enter the water. Soap is on the wall.
• Cameras stay in the locker. Photography is not allowed in the changing rooms or at the pools.
• Bring real swimwear. Sports shorts have been refused at the door; trunks or a swimsuit avoid the argument.
• Towels and swimsuits are for hire at reception if you arrive without them.
• The layout is confusing. The indoor pool, the outdoor deck and the hot tubs on the roof sit on different levels, and the toilets take finding.

Sundhöllin stands in Reykjavík, next to the Austurbæjarskóli school. There is accessible parking on site, and the entrance is step-free. From the door everything runs through reception: you pay there, then change and shower before reaching the pools.

Better: winter. Sitting in an outdoor hot tub while snow falls is the point of the place, and the pool draws few tourists.

Avoid: the outdoor changing areas and showers in cold weather — they are unheated.

Early mornings are the regulars' slot. Groups of older swimmers have trained here before the working day for years, enough that a documentary was made about them in 2010.