The one-acre, elevated Liberty Park opened to the public Wednesday. Built on top of a security center, it overlooks the memorial to those who died in the September 11 attacks.
The park includes the "Living Wall," a newly planted vertical garden, as well as a sapling grown from the horse chestnut tree outside Anne Frank's home in Amsterdam.
The park is modeled after Manhattan's High Line the abandoned railroad tracks that were transformed into one of the world's most visited green spaces.
Underneath the park, the security center will screen trucks, tour buses and other vehicles before they enter subterranean roads crossing the entire trade center.