Monemvassia and known by the Franks as Malvasia , is a well-known medieval fortress with an adjacent town, located on a small peninsula off the east coast of the Peloponnese in the Greek prefecture of Laconia. Its remains include the defensive structures and the small adjacent town and Byzantine churches , and its name derives from two Greek words, mone and emvassia, meaning "single entrance". Many of the streets are narrow and fit only for pedestrians ; the bay of Palaia Monemvassia is to be found in the north. Monemvassia's nickname is the Gibraltar of the East or The Rock. The rock is 300 m tall and 1.8 km long.