The island of Grótta is a unique natural pearl in the western part of the capital region. It is about 5 hectares and is connected to land in one part. There you will find unspoiled and unique nature. The shores south of Grótta, Seltjörn, and Bakkavík are suitable for outdoor activities and are rich in life that is worth the visit. The birdlife is very diverse and about 106 species of birds have been seen in Seltjarnarnes. Life in and around Bakkatjörn is interesting to observe and explore. From the beach, you can get out on foot to the island and stay there for about 6 hours. Flood and tidal information can be found in the flood table for the relevant month. There is also information about floods and tides on a sign by Gróttugrandi.

During the breeding season, from 1 May to 15 July, it is not allowed to go out in Grótta and closed to traffic. During the summer, you can find about 140 species of higher plants, which is about 1/3 of the total number of plant species in the country.