A nice UNESCO cover from Romania, depicting a miniature sheet issued in 2021 celebrating 30 years of Danube Delta as an UNESCO World Heritage Site. The Danube Delta (Romanian: Delta Dunării) is the second largest river delta in Europe, after the Volga Delta, and is the best preserved on the continent. The greater part of the Danube Delta lies in Romania (Tulcea County), with a small part in Ukraine (Odessa Oblast). Its approximate surface area is 4,152 km2, of which 3,446 km2 is in Romania. The Danube Delta, where the Danube river enters the Black Sea, is the largest European wetland. It is home to over 300 bird and 45 freshwater fish species. Important species include sturgeons, European mink, European wildcat, Eurasian otter, and the threatened monk seal.
