I've always loved the Arno; it was one of my grandmother's favourite places and we often used to go there.
It's always puzzled me as to why it was named after an Italian river but today, after a little research, I found this on the site "Old Wirral"
A document dating from the reign of Edward III, dealing with an enquiry into the question of
encroachments into the Forest of Wirral, treats with the occasion when Richard de Oxton was
called to account for having in his possession a quarter of a rood of land in Oxton, near
Arnehowe. At the period of this document, the use of the words erne, earn or arne, for eagle was
quite common. How is well-known as a word for hill, so could it have been that the name for the
Arno in medieval years was Eagle Hill?