Carlsten Fortress
Moderate17th-century fortress and prison
Tour the ramparts, cells and tunnels, and climb the round tower for a view over the whole archipelago.

In 60 seconds
Marstrand is a car-free island an hour north of Gothenburg, reached by a two-minute ferry from Koön. Above its harbour of painted wooden houses rises Carlsten Fortress, built after Sweden took Bohuslän from Denmark in 1658; for two centuries it was also a prison, and its most famous inmate, the thief Lasse-Maja, served his sentence there. In the 1800s Marstrand became the west coast's grandest bathing resort, and the summer society still gathers: the harbour fills with yachts, the hotels' verandas with lunches of langoustine and oysters. Walk right round the island on the coastal path — about an hour over smooth granite, with bathing rocks on the seaward side — then climb to the fortress for the view. A perfect day trip from Gothenburg, better as a night.
Best for
Known for
Skip if
You dislike crowds — on a July weekend Marstrand is packed with sailors and day-trippers; come midweek or in June.
Your match
Choose a few travel interests and we will show how well Marstrand fits them. Choose interests
See
The things that would make the trip incomplete without them.
17th-century fortress and prison
Tour the ramparts, cells and tunnels, and climb the round tower for a view over the whole archipelago.
Coastal path over the granite
About an hour round the island past coves and bathing rocks; the west side faces the open Skagerrak.
Wooden houses, yachts and the ferry
Painted summer houses, a 19th-century bathhouse society building and, in July, yachts moored ten deep.
Eat
A short list, kept short on purpose. Each entry answers one question: when is this the right choice?
Too few picks yet for their own heading, so they share this list.
Seafood and grill on the quay
Shellfish platters and grilled fish on a terrace over the water; book in summer.
Harbour-front hotel · Tenan, Verandan & Bakfikan
Langoustine, oysters and lobster on the veranda over the harbour, or Tenan's long-standing classics inside.
Island bakery since the 1930s
Cakes and cinnamon buns, and a queue on summer mornings.
Beyond the obvious
Less obvious, rarely queued for, and usually the part people remember.
The old spa society house
The bathing resort's assembly rooms from the years when King Oscar II summered on the island; now a restaurant and venue.
Orientation
How the city is actually divided, and what each part is for.
The old island town
Car-free, with the harbour, the church, the fortress and the coast path.
Stay
Areas rather than hotels — pick the right one and the rest follows.
Hotels and B&Bs on the island
Stay over to have the island to yourself once the day-trippers have caught the last bus back.
Practical
Plan this trip — useful links
Context
Enough to make what you are looking at legible.
Bohuslän passes from Denmark-Norway to Sweden; work soon begins on Carlsten Fortress.
Marstrand is made a free port, open to traders of any faith.
Marstrand becomes a fashionable bathing resort, favoured by King Oscar II.
Further out
Worth a day if you have one to spare.
Sweden's west-coast city
Gothenburg has its own guide; Marstrand is its favourite summer outing.
Fishing villages and granite islands to the north
Smögen, Fjällbacka and the Koster islands — Bohuslän has its own guide.