A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

America's first federal monument.

When you've got to go, you've got to go.

The largest catacomb system in the world.

Last remaining nuclear missile base in Ukraine.

Secret North Korean passage discovered below the world's most dangerous border.

Various forms of phallic art decorate this hill in commemoration of legendary local tragedy.

Peace Park and the Atomic Bomb Dome.

The Hanshin Expressway goes right through its 5th, 6th, and 7th floors.

The abandoned Japanese amusement park once loomed as a dystopian Disneyland.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

One of the longest water bridges in the world was built over a supposedly haunted swamp in Louisiana.

This famous bridge twisted itself into oblivion, but not for the reason you might think.

A forgotten remnant of the Soviet Union, Transnistria is an unrecognized country hidden behind a heavily militarized border between Moldova and Ukraine.

Sitting right on the border between East and West Jerusalem this modern art museum is in itself a symbol of Israel's hoped-for unity.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

This abandoned-looking amusement park is frighteningly open for business.

Stunning Roman aqueduct used for 1900 years and still standing.

The longest and tallest aqueduct in Britain can actually be sailed across.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

A bizarre collection of gifts to North Korean dictator Kim Jong Il from the despots of the world.

Eurasia's most difficult place to hang out, and farthest point from sea access.

Beijing's expansive subterranean hiding spot now crumbles away as a tourist destination.