The last four extravagant street signs of London's historic banking street.

London's amazing modernist public square that never was.

Rebuilt remains of a temple to Roman god Mithras.

This legendary stone is of unknown origin, and throughout history has been a literal touchstone for British leaders.

The commemorative stone column conceals a secret laboratory.

In Twickenham sits a small whitewashed castle that inspired Mary Shelley's 'Frankenstein.'

This foreboding medieval castle was twice besieged by barons rebelling against the English king.

This operational mill has survived centuries of destruction and construction.

This crumbling 14th century chapel became so unstable the roofing apparently collapsed during a wedding ceremony, narrowly missing the curate's head.

Rock carving created 1,300 years ago 75 feet off the ground.

This massive concrete sculpture is said to be the heaviest communist monument on Earth.

Crossing a suspension bridge above a forest is the only way to reach this 12th-century monastery.

Mysterious standing stone formations looks like a petrified forest.

Massive, unfinished broadcasting station stands as a monument to the fall of communism.

The site of many battles and tragedies, including the 40 maidens who leapt into the sea.

This once-grandiose behemoth of a monument from the socialist era now sits quiet and closed up.

The Grand Mall in Varna hosts one of the biggest collections of Soviet-era paraphernalia in Bulgaria.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

This museum is dedicated to the little known ancient Roman history of Vienna.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

On a winding Vienna side street, one museum has turned their windows into a monument to history’s peace-minded heroes.

The solemn exterior conceals an opulent interior of this 17th century church.

An exquisite Baroque church in Vienna's old town.

Order “Proletariat’s Cutlet” at this communist-themed restaurant allegedly once visited by Lenin.