A planet-hunting astrograph built in the 1920s to seek out the so-called "Planet X" beyond Uranus.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

The final resting place of the businessman-turned-astronomer who helped discover Pluto stands near his observatory.

Crafted in 1911, this steam locomotive spent its entire working life in Flagstaff.

This Czar-funded, onion-domed, lavishly muraled Orthodox Church played a starring role in "The Deer Hunter."

Once thought to be the fabled Holy Grail, it is now known to be an oil lamp.

Though the case is scorched and the buttons half-melted, this hardy handheld gaming device can still run a game of Tetris.

An aptly-named street near the birthplace of the modern LGBT rights movement.

This memorial honors thousands of enslaved Africans and their descendants who died in colonial New York.

Pulled from the rubble of one of the worst modern tragedies, a steel crossbeam became a symbol of hope for New Yorkers.

A stone marker commemorating the first time sound was transmitted over wires.

Dedicated to a colonial woman who was hanged for being a Quaker.

The former home of a Boston physician whose murder led to a revolution in forensic science.

Former home of an abolitionist couple who escaped slavery and established the most active Underground Railroad stop in Boston.

Like stepping into a spooky fairy-tale, this shop carries the dark ideas of artists and other makers.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

Could it have picked a better place to land?

Accessible only by boat, this centuries-old island fort never saw troops or combat.

The world's only international cryptozoology museum is host to an unrivaled collection of mysterious objects.

A mysterious shape catches the eye in this 16th-century painting.

A palatial former bank building now houses what may be the poshest art venue (and former Tesco) in Belfast.

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.