Rhodes is the largest of the group of islands known as the Dodecanese, and widely held to be among the loveliest of all the Greek islands. Among the enduring attractions of Rhodes are its attractive bathing beaches and well preserved ruins such as the Acropolis of Lindos, Ialyssos and Kamiros and the Castle of the Knights of Saint John, together with a fine museum. Medieval walls enclose the old town of Rhodes; around it spreads the modern town with broad, tree-lined streets, attractive shops and modern buildings.