Donnersberger

The island is reached by the Hakefjorden ferry, which leaves in Rönnäng, passes the island of Tjörnekalv and the Marstrand fjord, where the incomparable seascape spreads. Here you can see Åstol and Dyrön, the two car-free islands of very different character: while Åstol is the barren rocky island, the neighboring island of Dyrön looks lush green.In Nordhamnen on Dyrön, a contagious calm sets in. The largest motor vehicles on the island are the freight mopeds on the narrow, winding asphalt roads that connect Nordhamnen and Sydhamnen, past homes, green spaces, playgrounds and the year-round grocery store. Both ports are guest harbors with service and child-friendly bathing places. There is also a newsstand in Sydhamnen, and not far from the Bockeberget Gallery, which is open in summer and features art inside the mountain. From here, the line boats to Marstrand and charter trips to Gothenburg and Lysekil.
(Https://dyron.se/dyron)

Marstrand is a small town in the Swedish province Västra Götaland County and historical province Bohuslän. It is located about 30 km northwest of Gothenburg on the islands Marstrandsö and Koö in Kattegatt. Marstrand is located in the municipality Kungälv.Previously defined as a contiguous site, the Statistiska centralbyrån 2015 identified the district on the larger eastern island of Koö, also known as Arvidsvik, as an independent site Marstrand Arvidsvik. The older part of the village on the west offshore, separated by a strait about 200 meters wide island Marstrandsö is still called the village of Marstrand. The newer part of Arvidsvik today has more than twice as many inhabitants as the old Marstrand.
(Https://de.wikipedia.org/wiki/Marstrand)

Northwest of Alingsas you will find a well-known attraction that you should not miss when staying in the area. The natural history goal Brobacka usually ensures not only by seasoned nature lovers for enthusiasm. Brobacka lies between the two lakes Mjörn and Anten and is still the mirror image of the huge forces that worked during the Ice Age. Even today you will find here properties that are reminiscent of the imposing ice sheet. The melting of the inland ice released tremendous forces and created a landscape that could hardly be more breathtaking. The swirling masses of water created at Brobacka gigantic glacier mills, which are called by the locals as jättegrytor.In the rocks of Brobacka you will find both round and semi-circular shapes. The largest of these forms has an impressive diameter of 18 m. To Brobacka belongs today an interesting nature museum, which one should not miss during a visit. The Natural History Museum was set up in the buildings that once belonged to a former soldiers' village. On the summer weekends the museum can be visited. The numerous pieces that can be found in this inform about the flora and geology of the region. Starting from Brobacka, further destinations such as the Gräfsnäs castle ruin can be reached.Author: Nancy Fischer - Karsten@schwedenstube.de

Great pictures of the bridge up there I was not yet not completely afraid of heights :)