Halbinsel Holnis, Protected peninsula in Glücksburg, Germany

Halbinsel Holnis is a 360-hectare nature reserve northeast of Glücksburg on the Flensburg Fjord, protecting the peninsula's west and north coasts and adjacent fjord waters. Ice-age moraines form the Holnis cliff in the west, a steep coast designated a natural monument in 1978, while the south holds the diked Großes Noor and Kleines Noor, former beach lakes now drained grassland and brackish water.

The peninsula was already under nature-conservation care from 1982, when the Deutscher Bund für Vogelschutz and the Aktionsbündnis Grünes Glücksburg took it on. The town of Glücksburg applied for protection in 1983, and the reserve was established by ordinance on 30 April 1993 under number 155. The NABU Schleswig-Holstein branch manages it today.

The name Noor comes from a former beach lake: the Grosses Noor was diked between 1924 and 1929, the Kleines Noor already in 1870. Since the 1990s both areas belong to the Stiftung Naturschutz Schleswig-Holstein and are grazed extensively, partly by Scottish Highland cattle, which visitors can watch on the grassland.

Walking paths cross the area leading to viewpoints and along the coastline, with some sections passing through marshland or sandy terrain. Proper footwear and care on unmade paths are recommended, especially after wet weather.

The Große Noor was a Strandsee, a former beach lake, diked between 1924 and 1929; parts of its ground lie up to 2.5 metres below sea level and are drained by ditches and a pump. Since the 1990s the land has belonged to the Stiftung Naturschutz Schleswig-Holstein and is grazed extensively. A viewing tower in the south looks over it.