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

This modest post office sits on the site of H.H. Holmes' famous murder castle.

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

A lush green oasis in the middle of Chicago.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

Florida might be at its most surreal in this museum devoted to the famed Spanish artist.

This weeping, 10-foot-tall sculpture was a maquette for a 9/11 memorial.

A drab two-story office space in Delaware is a hidden tax haven for Hillary Clinton, Donald Trump, and over half the Fortune 500 companies.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A mysterious plaque to the even more mysterious "Fr. Pat Noise," killed in "suspicious circumstances."

Ireland's only German military cemetery holds the remains of a spy who was moved there under the cover of darkness.

The severed head of a 17th-century Irish martyr lies within an intricate golden shrine.

This 14th century tower house was once the home of Irish poet W.B. Yeats.

The Grand Lodge of Ireland is one of the oldest in the world, full of fantastical, elaborately themed rooms.

This modest plaza in Moneygall, Ireland has cashed in on its distant connection to the U.S. president.

Some of the saint's blood and bones are said to reside in Dublin.

Though they've since been renamed, these two streets hint at Dublin's darker days.

Mortarless walls that stretch for miles are a lovely solution for creating grazing land in the harsh terrain of the Aran Islands.

This European portal tomb has a capstone that weighs around 150 tons.

The world's tallest box hedge is found in a delightful garden.

An outstanding and haunting glimpse of the horrors of the Great Famine of Ireland.

A standing relief of a Norman knight whose posture marks him as a Crusader.

A hugely vast Irish landscape of barren rock that stretches for miles.