Juist is one of the seven inhabited East Frisian Islands at the edge of the Lower Saxon Wadden Sea in the southern North Sea, located between Borkum Island (west), Memmert Island (southwest) and Norderney (east). It is also a municipality in the district of Aurich in Lower Saxony in Germany.
Juist is 17 km long and 500 m to 1 km wide (this depends on the level of tide, which sinks and falls about 2.5 m in 6 hours). There are two villages on the island: the main village Juist, and Loog.
Juist can be reached from Norddeich train station and ferry port on the East Frisian mainland by the ferries of Reederei Norden-Frisia Frisia II, Frisia VI, Frisia IX, Frisia X at high tide - that means usually only once a day.
A non-tide-dependent way to reach the island is offered by the Airline FLN, though the weather conditions are sometimes - especially in winter - so bad that the airline has to cancel all flights for a day. Their 4-seated Cessna and their four 10-seated Britten-Norman Islanders serve Juist airport, which is the one with the second highest number of starts and landings in Lower Saxony after the capital airport Hannover.
The passage by ship takes about - depending on the wind and the waterlevel - 90 minutes, a flight takes just 7 minutes.
A natural specialty is lake Hammersee, a fresh water lake in the western third of the island. In the 17th and 18th century Juist was cut in two parts by several storm tides.
Around the year 1770 people started to close the 2 km wide burst at the southern side by a dune dike. As recently as 1928 the northern side was repaired. By the time the water in the lake turned from saltwater to freshwater.
Juist is - seen with the geologist's eye - nothing but sand. Rain water which drips into the sand has a lower density than saltwater, which makes a kind of fresh water bubble float over the saltwater around and deep under the island. That's why Juist island does not have a fresh water pipeline to the mainland - and made Hammersee turn into a fresh water lake.
Tourism is the main source of income for Juist's economy. In almost all the buildings on the island are guestrooms. There are also several hotels and a youth hostel.
The island is popular for people having respiratory complaints because of the unpolluted air.