The Danube Delta is the second largest delta in Europe, after the Volga River Delta, and the best preserved on the continent. The greater part of the Danube Delta lies in Romania (Tulcea County), while its northern part, on the left bank of Chilia channel, is part of Ukraine. The approximate surface is 4150 square km, of which 3445 square km are in Romania. If we include the lagoons of Razim-Sinoe (1015 sq. km of which 865 sq. km of water surface), located south of the delta, but related to it geologically and ecologically (their combined territory is part of the World Heritage Site), the total area of the Danube Delta reaches 5165 sq. km.
The Danube Delta is a low alluvial plain, mostly covered by wetlands and water. It consists of an intricate pattern of marshes, channels, streamlets and lakes. The largest lakes are Dranov (21.7 sq. km), Roşu (14.5 sq. km) and Gorgova (13.8 sq. km). At the entrance of the Delta Danube river divides into three channels, Chilia, Sulina, and Sfintul Gheorghe. The last two branches form the Tulcea channel, which continues as a single body for several kilometers after the separation from the Chilia. At the mouths of each channel gradual formation of new land takes place, as the delta continues to expand.
The Danube Delta is part of the eastern European steppe ecosystem, with Mediterranean influences. As a young region in full process of consolidation, the Danube Delta represents a very favorable place for the development of highly diverse flora and fauna, unique in Europe, with numerous rare species. It hosts 23 natural ecosystems, but due to the extent of wetlands the aquatic environment is prevalent; the terrestrial environment is also present on the higher grounds of the continental levels, where other ecosystems developed. Between the aquatic and terrestrial environments, is interposed a swampy, easily flooded strip of original flora and fauna, with means of adaptation for water or land, depending on the season or the hydrological regime.
Situated on major migratory routes, and providing adequate conditions for nesting and hatching, the Danube Delta is a magnet for birds from six major eco-regions of the world, including the Mongolian, Arctic and Siberian. There are over 320 species of birds found in the delta during summer, of which 166 are hatching species and 159 are migratory. Over one million individuals spend the winter here.
Due to its vast variety of fauna the Danube Delta is very often visited by the tourists for sport fishing and bird watching, many vacation villages and hotels developed and cruise ships sail thru, every summer.