Helsinki Islands Guide: Vallisaari, Lonna and Pihlajasaari Beaches

While the HSL municipal ferry carries most visitors straight to Suomenlinna, more than three hundred other islands dot the Helsinki archipelago. Between May and September, regular seasonal waterbuses depart from the Market Square (Kauppatori) and Merisatama/Ruoholahti to three distinct car-free islands that show how locals spend sunny summer weekends.

1. Lonna (7 minutes from the Market Square on the FRS Waterbus)

Sitting right along the ferry channel just north of Suomenlinna, tiny Lonna is a rocky islet barely 150 metres long that served in the 19th century as a Russian naval mine-storage depot and in the 1940s as a demagnetising station to protect ships from magnetic sea mines. Opened to the public in 2014, its restored 1880s red-brick warehouses now house a warm seasonal organic bistro and coffee bar, while at the northern tip sits Lonna Sauna, a public two-storey loft sauna designed by OOPEAA Architects entirely from hand-hewn Finnish logs with wood-fired stoves and steps leading down into the Baltic Sea (book Lonna Sauna slots well ahead online).

2. Vallisaari and Kuninkaansaari (20 minutes from the Market Square)

Lying immediately east of Suomenlinna across the narrow Kustaanmiekka strait, the twin linked islands of Vallisaari and Kuninkaansaari were closed to the public as a restricted military munitions zone for a hundred years until 2016. Because virtually no one lived here for decades, wild nature reclaimed the 19th-century Russian brick fortifications, creating the richest biodiversity in the Helsinki region (home to over a thousand butterfly species and bats). Follow the signposted 3-kilometre Alexander's Route and 2.5-kilometre Kuninkaansaari Loop along cobblestones and forest paths up to the Alexander Battery viewpoint for a sweeping view back across Suomenlinna and Helsinki.

3. Pihlajasaari ("The Rowan Island", 10 minutes by boat from Merisatama or Ruoholahti)

Reached from the southern waterfront at Merisatama (at the foot of Ullanlinna / Kaivopuisto) or Ruoholahti, twin-island Pihlajasaari is Helsinki's favourite summer beach escape. Lined with sandy coves, smooth sun-warmed granite rocks, forest nature trails and a famous row of brightly painted 1930s wooden beach changing cabins in red, blue, yellow and green, it feels like a vintage Baltic resort ten minutes from downtown.