It would be a mistake to regard the Rhine’s numerous ferries merely as a means of transport. They are quite an institution in their own right and are as much a part of the Rhine valley as the castles and the wine. They have a long tradition: there have been ferrymen on the Rhine since the Middle Ages. There were once treacherous shallows and dangerous rocks here and only a person with a profound knowledge of the river could be sure to get his passengers to the other side safe and dry. Great skill and experience are still required today, as the ferries operate on one of Europe's busiest shipping routes. The Rhine is an important inland waterway and still plays a significant role as a transport route. The boats and ferries are not just nostalgic relics from the past; they are an integral part of everyday life on the Rhine. Bridges are few and far between in this part of the world and are concentrated in the Koblenz area, and so up and down the river the ferries are a typical part of the local scene. Between the sister towns of St. Goar and St. Goarshausen they even provide the venue for the "Festival of the Flying Bridge". The Easter tradition associated with the "Flying Bridge" (a ferry that uses the force of the current to move it across the river) dates back to the 16th century when the first ferries crossed the Rhine on ropes between St. Goar and St. Goarshausen. At Easter time it was usual for passengers to give the ferryman an egg in payment for the crossing.