Porto Venere is a UNESCO World Heritage Site. The Church of San Pietro, consecrated in 1198,‎ sits on a promontory, once the site of a temple to Venus (Venere in Italian) from which Porto Venere gets its name. Nearby is Byron's Cave in a rocky area leading to the sea where the poet Byron used to swim.
Reference: http://it.wikipedia.org/wiki/Porto_Venere