Now known chiefly as the promenade buffer between lower Manhattan's corporate bustle and the long lines of tourists waiting for ferry trips to the Statue of Liberty and Ellis Island (and as the namesake for the pleasant if dull residential development stretching north from the park along the Hudson River), Battery Park is a large, shady, pedestrian-oriented park enclosing 21 acres, the southern tip of Manhattan, and a hugely disproportionate amount of history. At the center of the park sits Castle Clinton, a round, ancient-looking fort built on a small island in New York harbor to help defend the city during the war of 1812 (and later enclosed by extending the landmass of Manhattan Island artificially southward). The Castle, however, is not the battery for which the park is named. That honor belongs to a long-disappeared artillery base which once stood near here during colonial times, manned alternately by the Dutch and British. Later leased by the city, the castle became a popular beer garden, then, roofed, a leading theater venue that played an important role in the development of the city's robust dramatic culture, the main immigration depot from 1855 until Ellis Island opened in 1892 (ushering in all the Irish immigrants fleeing the potato famine), an aquarium, and now a modest local history museum and, perhaps most importantly, the place to buy ferry tickets.