Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

A beautiful Greco-Roman structure houses a well once believed to have healing powers.

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

The fountain marks the area where hundreds of accused witches were burned at the stake.

One of the oldest family businesses in Reykjavík serves lamb-based hot dogs.

An encyclopedic collection of mammal penises.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

An important Mayan religious and trading center dating back to 200 BC.

A massive underwater sinkhole made famous by Jacques Cousteau.

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

The modern birthplace of Irish freedom.

Amidst the bustling streets of Dublin, there is a hushed garden that is dedicated to "All those who gave their lives in the cause of Irish Freedom."

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

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The oldest working mechanical clock in the world.

Famously misunderstood wonder of the ancient world

Once designed as the entrance to Buckingham Palace, this structure was later relocated and stands as a victory arch.

A memorial for public executions that dates back to the 14th century.

Outside of one of Britain's most renowned social clubs, a step installed specifically for the Duke.

One of America's founding fathers lived in this London lodging between 1757 and 1775.

At the top of the hour, figures of the London department store's two co-founders emerge and bow to each other.

The Great Fire of London and the regulation of one-way streets both started in this alley.