Danube River is home to many mammals, birds and fish species, including numerous endangered ones. Important bird species are cormorant, pelican species, white-tailed eagles, mute swans and the European kingfishers. The Danube River delta is among the largest and best preserved European deltas and consists of numerous lakes and marshes.

Since ancient times, the Danube has been an important trade route in Europe. The river is also a vital source of hydropower and drinking water. Danube River is a natural border between Bulgaria and Romania, currently with two connecting bridges Vidin – Calafat (New Europe Bridge) and Russe – Giurgiu (formerly known as the Friendship bridge).