Grünes Kliff, Coastal nature area in Keitum, Germany.

Grünes Kliff is a grass- and herb-covered slope in Keitum on Sylt, about 13 metres high, marking the transition from the island's higher geest to the marsh strip by the Wadden Sea. It runs roughly 3 km from the southeastern edge of the village centre to the church to the north, along the coastline.

The slope formed through natural coastal processes over thousands of years as waves and weather continuously shaped the shoreline. Over time, efforts were made to protect the cliff from further erosion and preserve this distinctive feature.

The name Grünes Kliff, Green Cliff, comes from the grass and wild herbs covering the slope, unlike the bare red cliffs elsewhere. The Danish name Kejtum Klev and North Frisian Kairem Klef both refer to the same cliff at Keitum. Near the Sylt Museum stands the bronze "Tisch am Kliff", made in 2019 by five artists with reliefs on 5000 years of island history.

The slope runs about 3 km from the southeastern edge of Keitum's old core to Keitum Church, following the coastline. The Sylt Museum, the old Frisian house and the Harhoog and Tipkenhoog burial mounds lie along it. The surface is grass and low shrubs, so wear sturdy shoes; the open Wadden Sea side is exposed to wind.

The partnership between vegetation and coastal protection is clearly visible here, as plants actively help stabilize the shoreline against erosion. This natural buffer against storm surge represents how decades of work have shaped the current landscape.