There are five larger islands and ten tiny islets. The names of the large islands are Sylt, Föhr, Amrum, Nordstrand and Pellworm. The islets are called Halligen. In medieval times the present day islands Nordstrand, Pellworm as well as the Halligen were part of the large island of Strand. This island was torn to pieces in a disastrous stormtide in 1634.
Sylt is the largest of the North Frisian Islands, containing about 100 km². It is accessible by a dam called the Hindenburgdamm; this dam is only accessible to trains. In the summer months the island is crowded with tourists, including those who have a preference for nudism. Sylt's image is that of a meeting-point for the jet-set. The main town on the island is Westerland. The northern end of Sylt, the Ellenbogen ("elbow"), is the northernmost point of Germany.
Compared with Sylt, Föhr is a lonely and silent island. Its area is 82 km². Sixteen old hamlets are scattered over the island; some of them already existed in the 13th century. The main town is Wyk at the eastern coast. There is no bridge or dam connecting Föhr and the mainland, so ferries are the only connection.
Amrum is only 20 km², but it is popular with tourists, though less crowded than Sylt. The western half of the island features a beach 12 km in length and 1 km in width. The villages are situated at the eastern coast, with Wittdün being the most important of them.
Pellworm and Nordstrand are the remains of the submerged island of Strand. The main town of this sunken island was Rungholt, thought to be the largest town in the surrounding area, but totally destroyed and submerged by a storm in 1362. Two and a half centuries later, in 1634, another storm tore Strand to pieces. Nordstrand has an area of 49 km², Pellworm 37 km².
Smaller remains of Strand are the ten islets called Halligen. The houses on these tiny islets are built on artificial hills. In a storm tide only these hills rise above the sea, while the remaining islet is flooded. The names of the Halligen are Nordmarsch-Langeness, Norderoog, Süderoog, Nordstrandischmoor, Oland, Südfall, Gröde-Appelland, Hooge, Habel and the Hamburger Hallig.