This posh mansion began as a family's estate and ended as the site of a murder ripped from the pages of a pulp novel.

This picturesque cliffside beacon no longer calls to sailors but shines once a year in honor of a famous shipwreck.

Secret hideaway for an alternative beach experience.

The only arched bridge made of stone on the entire Mississippi River.

At this Minnesota state park you can easily wade across the source of the mighty Mississippi.

This bright yellow building is packed with sweet treats from all around the world, from chocolate-covered crickets to whoopie pies.

A toweringly silly piece of modern art has been delighting locals since the 1980s.

A battle between nature and architecture in the Cambodian jungle.

Triangular House built on a leafy residential street in St. Paul.

When flour explodes, it's not a pretty sight.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A violent name for a violent volcano.

A gallery of underwater art that can be visited by man and fish alike.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

The final resting place of the great navigator, or maybe his brother.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

20,000 pieces in a Frank Gehry-designed building.

This iconic water tower and failed bandstand is open for panoramic views once a year.