Alviano is a small town not far from Orvieto, in Umbria,in the Tevere valley, surrounded by woods and hills.
In 1963 the Tevere river was blocked in its way with a dam and so a lake has formed at the foot of Alviano.
Now the lake is a marsh , the OASIS of Alviano, where lot of birds can find food all through the year or built their nest or spend the winter.