Barely poking out of the East River off the coast of Manhattan is tiny U Thant Island, a barely noticeable mound of greenery with some strange metal scaffolding rising from its base, that are actually Buddhist monuments.

The little islet is the result of one of New York’s many subway tunnels. Officially the name of the scrap of land is “Belmont Island” and it didn’t even exist until the late 1800’s when a trolley tunnel was dug beneath the East River, connecting Manhattan with Queens. As waste from the tunnel’s construction built up on a preexisting reef beneath the surface, the island slowly began to emerge above the water level. By the end of the tunnel’s construction a new landmass was born.

Initially the freshly born land was named after the financier who finished the tunnel, August Belmont Jr., but in 1977 a Buddhist group rented control of the island from the city and unofficially renamed it after former United Nations Secretary General U Thant, building a skeletal metal arch adorned with mementos of the leader. A sign was also placed on the island heralding its new name, ensuring that it would stick in the decades to come.

Today the island is off-limits but eagle-eyed sightseers can view it from the shores of Manhattan and Queens or the southern tip of Roosevelt Island, or pass beneath it on the 7 train that now operates in the old tunnel.