Skip sultry southern Europe and head to these cool, uncrowded islands instead

Kvarken Archipelago: best for geological wonders

While climate change threatens sea level rise almost everywhere in the world, the opposite is happening here. Crushed by an ice sheet 10,000 years ago, the land is slowly recovering at half a centimeter per year. Though you won’t move the earth, the effects are obvious: once-submerged boathouses are stranded ashore, beaches are turning into forests, and many more islands are emerging from the sea. Climb an observation tower on Svedjehamn to study the meandering De Geer moraines, another geological curiosity.

How it goes: Observe the scenery from Kalle’s Inn Glasshouses on Soderudden. From £264 per night for two people with breakfast (coolstays.com)

Hailuoto, Oulu: best for bird watching

Over the year, more than 300 bird species have been sighted in the wetlands of this northern Baltic Sea island. High above the meadows and reeds, several birdhouses offer excellent viewing platforms. Spread your own wings a little further by visiting a crumbling lighthouse, colorful fishing villages and an organic craft brewery. And discover why lichen forests and sculpted dunes have attracted artists since the early 20th century.

How it goes: Luotsihotelli – Arctic Lighthouse Hotel has double rooms from £92 with breakfast (expedia.co.uk)

Suomenlinna: best for history

It takes less than 20 minutes to reach one of Finland’s most important Unesco World Heritage sites from the mainland, but a visit will take you back more than 200 years. Originally built by the Swedes, a sea fortress straddles several islands in the Helsinki archipelago with museums, bunkers and a WWII submarine open to the public. Guided tours take place throughout August, along with short trips on a traditional sailing ship.

How it goes: For the full maritime experience, stay at Villa Silo, a 19th-century wooden house in Russia’s merchant quarter. From £211 per night for four (airbnb.co.uk)

Pellinge: best for Moomin fans

As Finnish as saunas and Santa Claus, Moomins embody a national Nordic spirit. Creator Tove Jansson found inspiration for many of her stories on the tiny island of Klovharun, where she owned a summer home. The artist’s former home, now managed by a heritage group, is only open for a week each July. But it is possible to explore the landscapes that inspired her work. The Pellinge Islands are a two-hour drive from Helsinki and are part of the Porvoo Archipelago.

How it goes: Pellinge Cottages have several rental properties including the Dalen beach cottage (sleeps six) from £493 per week (+358 400 670 785; pellingecottages.fi)