Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Breathtaking and huge 430 year old maps of Italy.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

An Iron Age fort on the edge of a seaside cliff offers a glimpse into an ancient, mystical world.

One of only three fountains created by the iconic architect Friedensreich Hundertwasser.

A "miracle" that seems to produce more holy fistfights than holy revelations.

Street artists transformed an abandoned air vent into the beloved Star Wars robot.

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

A cheeky architectural easter egg.

In the midst of a living monument to Soviet social engineering, Polish Catholics built this church by hand.

Real bones which are said to have belonged to a Polish dragon.

This man-made mound monument was built out of soil from all across the Polish empire.

The stunning interior of this Gothic church is covered in ornate gold details.

The Guardian of Tallinn.

A brush maker used his factory to protect blind Jews from the Gestapo.

Never actually a tree at all, this spot was the site of London's public hangings for nearly 600 years.

Since 2017, the remains of Stretford's industrial past have been occupied by a collection of gnomes.

The longest sculpture trail in the United Kingdom.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

A building shaped like the Army Corps of Engineers logo, because why not?