Major islands in Helsinki include Seurasaari, Vallisaari, Lauttasaari, and Korkeasaari – the latter being the site of Finland's largest zoo called Korkeasaari Zoo. Other noteworthy islands are the fortress island of Suomenlinna (Sveaborg), the military island of Santahamina, and Isosaari. Pihlajasaari island is a favorite summer spot for gay men and naturists, comparable to Fire Island in New York City.