Nidingen is a nature reserve and has one of Halland's finest bird sanctuaries. Here is for instance Sweden's only flock of a three-toed sea gull. The vegetation has been strongly affected by the weather. Characteristic plants are orach, sea-cale, thrift and sagebrush.
The island Nidingen is 1 km long and 300 m wide. The island is the visible part of an end moraine. A variable and treacherous reef surround the island.
Nidingen was Swedens first lighthouse and was probably the worlld's first double lighthouse. In 1624 the first fire lighted lighthouse was lit on the island. In 1832 two lighthouses wese built and in 1945 they were replaced by an automatc lighthouse. The two older lighthouses have been renovated and are open for the public. The lighthouses are now computerized but Nidingen is still manned. Here is an autimatic weather station.