Isopu Tower (Maltese: Torri ta' Sopu), also known as San Blas Tower or Torre Nuova, is a small watchtower situated on the cliff between San Blas and Daħlet Qorrot in Nadur, Gozo, Malta.Isopu Tower was the last watchtower to be built in Malta, apart from the tour-reduits of the 18th century. It is one of four surviving towers on Gozo, with the others being Xlendi Tower, Dwejra Tower and Mġarr ix-Xini Tower.