If you are walking about the harbor, stop by this 16th-century tower which protected the Portoferraio harbor and serves as a lighthouse now.
Wikipedia (Italian) http://it.wikipedia.org/wiki/Torre_della_Linguella
Info Elba http://www.infoelba.it/isola-d-elba/territorio-storia/luoghi-da-visitare/forti-fortezze/torre-linguella/
Address Pianosa - Portoferraio, Italy
Coordinates 42°48'42.775" N 10°19'47.629" E