Aveiro

The presence of human settlement in the territory of Aveiro extends to the period associated with the great dolmens of pre-history, which exist in most of the region.
For a long period Aveiro was important economic link in the production of salt and commercial shipping.It was a centre of salt exploration by the Romans and trade since 26 January 959 (from the testament of Countess Mumadona Dias to the cenóbio of Guimarães). During this testament, Mumadona Dias also highlighted the ancient name for Aveiro, referring to the monastery's lands in Alauario et Salinas, literally, "a gathering place or preserve of birds and of great salt".
The Moors invaded and then held it until the 11th century, after which it became popular with Portuguese royalty.
It is known as the Venice of Portugal