Gothenburg

Near Gothenburg is the beautiful southern archipelago. There's a resident population on most islands, so ferries run all year. Private cars are not allowed. Take tram 11 or 9 in summer to Saltholmen, and then one of the ferries to Styrsö, Köpstadsö or any of the other islands. Here you can swim in the ocean, buy ice cream and maybe eat at the restaurants on Brännö, Styrsö or Vrångö. Be warned that the tram is packed with people on sunny summer days, especially when the 9 doesn't run, and going by car isn't better since you are unlikely to find a parking place. The ferries, however, usually make extra tours such days.

Styröbolaget provide a folder (http://www.styrsobolaget....) with more information about the islands.

Älvsborgs fortress

Älvsborgs fästning from the 17th century was built on an island to protect the city from being attacked from the sea. Tourist boats (http://www.stromma.se/en/...) make the trip regularly during summer.

Vinga

the last outpost before the sea and the place where Evert Taube a famous Swedish poet grew up.

Gunnebo House and Gardens

[ (http://www.gunneboslott.s...)], in the neighbouring municipality of Mölndal, is a large 18th century wooden mansion built in the neo-classical style with Rococo interiors set in a Baroque park. There is a restaurant, a gift shop, guided tours and annual markets in the autumn and at Christmas.

Tjolöholm Castle

in Kungsbacka municipality south of Gothenburg, is an anachronistic Tudor castle built in the years around 1900 for the Scottish-Swedish merchant and factory owning family Dickson, one of Gothenburg's many generous donors they founded Gothenburg's first public library and built decent homes for the families of their factory staff.