Castle Clinton

In front of you is a round fort of reddish stone that looks oddly out of place among gardens and towers. When it was built, between 1808 and 1811, it was not on dry land at all: it stood on a small artificial island off the shore, linked to Manhattan by a wooden bridge. Everything you are standing on around it is landfill added later.

1A fort without a battle

It was first called the West Battery and carried 28 cannons to protect the harbor from a possible war with Britain. War did come in 1812, but the British never attacked New York, and the fort never fired at an enemy. In 1815 it was renamed Castle Clinton, after DeWitt Clinton, the city's mayor.

2From concert hall to America's front door

In 1824 the city leased it as an entertainment venue called Castle Garden. In 1850 the Swedish soprano Jenny Lind sang her first American concert here, promoted by P. T. Barnum. In 1855 the building changed lives again: it became the immigrant landing depot, the predecessor of Ellis Island. Until 1890, somewhere between seven and a half and eight million people passed through it.

Before Ellis Island, this stone circle was the first address in America for millions of newcomers.

Next it became the New York Aquarium, from 1896 to 1941. It escaped the wrecking ball in the 1940s and was declared a national monument in 1946.

3What to look for

• The gun ports in the wall, where the cannons once poked out.
• The thickness of the stone in the entrance passage.
• The view of the harbor: the Statue of Liberty and Ellis Island, which took over this fort's role.