Hidden beneath the streets of London is a secret subway that only carried mail.

Eighty million natural history specimens call this gargantuan museum home.

A gallery specifically dedicated to the botanical illustrations of a remarkable traveling lady.

Famously misunderstood wonder of the ancient world

Ancient mysterious ruts carved in the bedrock.

This prison on the Maltese island of Gozo is almost 500 years old, and they have the graffiti to prove it.

Quite simply the largest tree in the world (by volume).

This Stone Age solar temple aligns with the sun on each equinox and solstice.

After nearly 60 years, there's still a bear at Paddington Station looking for help.

The rose garden in Regent's Park where Pongo and Perdita met for the first time in Disney's "101 Dalmatians."

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

A striking public sculpture representing the period of martial law in Communist Poland.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

Rotterdammers' dirty minds gave this Santa a dirty nickname and cursed it to a life of wandering.

Built by crowdsourcing, this wooden foot bridge saved a part of Rotterdam that was languishing in wait of city funding.

The broken skateboards that became a poignant memorial to a murdered skater.

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.

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

The oldest licensed distillery in Ireland.

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

This singular Irish dolmen is more Frank Lloyd Wright than upright stonehenge.

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

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