Legend has it that Jason and his Argonauts were the first of the ancient mariners who sailed into the Black Sea in their quest for the golden fleece. Locked between Europe and Asia, this inland sea is almost completely isolated from the Earth’s oceans, its only connection is through the natural strait of the Bosphorus, one of the world’s most significant waterways. The Danube is one of the most important of the many rivers that flow into the Black Sea. Its vast delta is home to a rich and beautiful collection of flora and fauna, which makes it both a fascinating river cruise destination.