Куршская коса: уникальный ландшафт Балтийского моря

Sand dune spit on the Baltic

The Curonian (Courish) Spit (; Ку́ршская коса́; Kurische Nehrung; ) is a long, thin, curved sand dune spit that separates the Curonian Lagoon from the Baltic Sea. It is a UNESCO World Heritage Site shared by Lithuania and Russia. Its southern portion lies within Kaliningrad Oblast of Russia, and its northern within southwestern Klaipėda County of Lithuania.

The Curonian Spit stretches from the Sambia Peninsula on the south to its northern tip next to a narrow strait, across which is the port city of Klaipėda on the Lithuanian mainland. The northern long stretch of the Curonian Spit peninsula lies in Klaipėda County, Lithuania, while the rest is part of Russia's Kaliningrad Oblast, Russia. The width of the spit varies from a minimum of in Russia (near the village of Lesnoy) to a maximum of 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. It depends on a dynamic balance between sand transport and deposition. It is, geologically speaking, an ephemeral coast element. The most likely development is that the shallow bay inside the Curonian Spit will eventually fill up with sediment, thus creating new land.

According to folk etymology for the name of Neringa Municipality, there was a giantess girl named Neringa, who formed the Curonian Spit and helped fishermen.

From c. 800 to 1016, the Spit was the location of Kaup, a major pagan trading centre which has not yet been excavated. The Teutonic Knights occupied the area in the 13th century, building their castles at Memel (1252), Neuhausen (1283), and at Rossitten (1372). After the Thirteen Years' War (1454–1466), the spit became part of a Polish fief held by the Teutonic Knights. The spit may have been the home of the last living speaker of now extinct Old Prussian, one of the Baltic languages.

Significant human impacts on the area began in the 16th century. Painters from Königsberg such as Julius Freymuth visited the area, as did poets like Ernst Wiechert and Carl Zuckmayer.

While today the Kursenieki, also known as Kuršininkai, are a nearly extinct Baltic ethnic group living along the Curonian Spit, in 1649 Kuršininkai settlement spanned from Memel (Klaipėda) to Gdańsk. The Kuršininkai were eventually assimilated by the Germans, except along the Curonian Spit where some still live. The Kuršininkai were considered Latvians until after World War I, when Latvia gained independence from the Russian Empire, a consideration based on linguistic arguments. This was the rationale for Latvian claims over the Curonian Spit, Memel and other territories of Prussia, which would be later dropped.

The Curonian Spit is home to the highest moving (drifting) sand dunes in Europe. Their average height is , but some attain a height of 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 holiday resort, mostly frequented by Lithuanian and German tourists.

Parnidis sand dune, subjected to drift by harsh winds, is rising up to above sea level. Local residents believe that the name Parnidis comes from the phrase meaning "passed across Nida", because this wind blown dune has several times passed through the village of Nida. Scientists estimated that each person climbing or descending on the steep dune slopes moves several tons of sand, so hikers are allowed to climb only in designated paths. There is a granite sundial built on Parnidis dune in 1995 that accurately shows the time. The sundial was rebuilt in 2011 following storm damage. The sundial is a stone pillar high and weighing It consists in small steps covered with granite slabs, carved with hour and half hour notches, as well as one notch for each month, and four additional notches for solstices and equinoxes. From the astronomical point of view Parnidis dune is an ideal place for the sundial in Lithuania.

There are 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 the unique nature and the economy would be damaged. The construction of an offshore drilling facility (the Kravtsovskoye (D 6) oilfield) in the territorial waters of Russia, from the coastline of the Curonian Spit raised concerns over possible oil spills. Between 2002 and 2005 local environmentalists in 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. These concerns did not engender support in the government of Russia. They were, however, supported by the government of Lithuania. The oilfield is about from the boundary of Lithuanian territorial waters; the prevailing northward currents means that the Lithuanian coastlines would receive much potential damage in case of leakage. Opposition to the operation of D 6 met little international support, and the oil platform was opened in 2004. During the first decade of the 21st century the two states agreed to a joint environmental impact assessment of the D 6 project, including plans for oil spill mitigation. The assessment and mitigation project had not been completed as of 2010. Another concern is that increased tourism destroys the very nature that attracts it. For this reason, protective measures have been taken, such as banning tourists from hiking in certain areas of the spit. Natural hazards are more dangerous in the Curonian Spit than elsewhere in Lithuania or the Kaliningrad Oblast. For example, storms tend to be stronger there. Due to the importance of trees in preventing soil erosion, forest fires that happen in summer are more dangerous to the ecology.