The Curonian Spit is a 98 km long, thin, curved sand-dune spit that separates the Curonian Lagoon from the Baltic Sea coast. Its southern portion lies within Kaliningrad Oblast, Russia and its northern within southwestern Lithuania. It is a UNESCO World Heritage Site shared by the two countries.
The Curonian Spit stretches from the Sambian Peninsula on the south to its northern tip next to a narrow strait, across which is the port city of Klaipėda on the mainland of Lithuania. The northern 52 km long stretch of the Curonian Spit peninsula belongs to Lithuania, while the rest is part of the Kaliningrad Oblast, Russia (see the map). The width of the spit varies from a minimum of 400m in Russia (near the village of Lesnoy) to a maximum of 3,800 m in Lithuania (just north of Nida).
The Curonian Spit was formed about 3rd millennium BC. A glacial moraine served as its foundation; winds and sea currents later contributed enough sand to raise and keep the formation above sea level. The existence of this narrow shoal is inherently threatened by the natural processes that govern coastal shoreline features. It depends on a dynamic balance between sand transport and deposition. If (hypothetically) the source area to the south-west were cut off, say, by a large port construction with a pier, the Spit would erode and eventually disappear. It is thus a geologically speaking ephemeral coast element. The most likely development, however, is that the shallow bay inside the Spit will eventually fill up with sediment, thus creating new land.
The Curonian Spit is home to the highest moving (drifting) sand dunes in Europe. Their average height is 35 meters, but some attain the height of 60 meters. Several ecological communities are present on and near the Spit, from its outer beaches to dune ridges, wetlands, meadows, and forests. Its location on the East Atlantic Flyway means it is frequently visited by migratory waterfowl. Between 10 and 20 million birds fly over the feature during spring and fall migrations, and many pause to rest or breed there.
The largest town on the spit is Nida in Lithuania, a popular holiday resort, mostly frequented by Lithuanian and German tourists. The northern shoreline of Curonian Spit is the site of beaches for tourists. Both the Russian and Lithuanian parts of the spit are national parks.
There are various environmental concerns related to the Curonian Spit, which is often promoted as a refuge of clean nature. Due to the importance of tourism and fishing for the regional economy, pollution of sea and coastlines may have disastrous effects for the area as both the unique nature and the economy would be damaged. The construction of an offshore oil-drilling facility (the Kravtsovskoye (D-6) oilfield) in the territorial waters of Russia, 22.5 kilometres from the coastline of the Curonian Spit raised concerns over possible oil spills. Between 2002 and 2005 local environmentalists in both Kaliningrad Oblast and Lithuania protested against Lukoil's plans to exploit the oilfield, objecting to the possible great damage to the environment and tourism (a vital source of income in the area) in case of oil leakage.