On Krossøy the arable land and buildings lie at the east side of the island, with the farmyards drawn a little back from the sea and the boatsheds. A well built stonewall delimits the arable lands from the outlying fields. From the dwelling houses there is one path to the hayshed and one to the sea. Fishing has been the main activity out here by the sea; agriculture has been adapted to the daily household. On one of the holdings, there is even a complete smithy with bellows, fireplace and tools.
The harbour lies protected by some rocks. The buildings for the marine use lie in a tight cluster, placed with care, sheltered from the heavy pull of the sea after storms in the ocean. Here are boathouses, sea-houses and peat-houses. On the islands peat was cut and was stored here. Quays, stacks and heaps are constructed in granite, the sea-houses are frame-built, most of them from the end of the 1800s. Cultural landscape and buildings on Krossøy form a rare harmonic entity. The marine use environment has a high status for protection in a countrywide context.
The oldest school in Rongevær was built in 1909. In 1933 it was moved to one of the neighbouring islands, Lyngkjerringa. The schoolhouse today is being used as centre for courses and seminars at Rongevær, which is a popular venue for seminars.