An ancient stone fortress considered by many to be the eighth wonder of the world.

The world's tallest slum.

This unique depiction of the Virgin Mary may be the tallest kinetic art sculpture in the world.

A careful eye can find hundreds of dinosaur tracks running along the Connecticut River.

The largest permanent Monopoly board makes one of the longest games even bigger.

A giant chess set, minus the psychedelic drug trip.

An enigmatic mural hiding in plain sight in one of São Paulo's busiest metro stations.

Try not to get lost in this picturesque Brazilian labyrinth of the dead.

A comprehensive collection of Pez dispensers.

Breathtaking Byzantine paintings cover the inside of this 12th-century church.

The oldest Dutch colonial stone house in New York City is a hidden gem on the border of Brooklyn and Queens.

This abandoned, partly demolished building is now home to beautiful graffiti and murals.

Once the site of a 12-century monastery, this tiny island is now home to only five permanent residents.

A giant concrete orb in far north Iceland marks the ever-shifting boundary.

Built as a home for the Union Porcelain magnate in 1867, now the Greenpoint Reformed Church and home to a ceramic mystery.

Church featuring "high Victorian gothic" architecture.

The world's largest collection of materials relating to lesbian history is housed in a Brooklyn townhouse.

A charming "tea atelier" hidden away in Greenpoint, Brooklyn.

The world’s largest underwater sculpture is found just off the coast of Nassau.

A six-story treehouse offers spectacular views of New York's Finger Lakes region.

MIT students continue the legacy of beloved professor "Doc" Edgerton through learning by doing.

This famous writer's tombstone is a literary pilgrimage site that was publicly defiled by a rival.