The intended purpose of this unfinished Elizabethan building remains a mystery.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.

This bridge is the first to be made entirely from iron, but designed like it was still made of wood.

Beneath the city of Lourdes, France is a massive, concrete church.

A cluttered and astounding collection of antiquities and curiosities.

Largest lake in Great Britain measured by surface area.

A 18th century graveyard and its astonishing cortege of macabre iconography.

This extraordinary geological oddity resembles human-made pavement.

Relics of Australia's convict past, and a modern scene of unimaginable horror.

This single room has survived the centuries with almost no deterioration.

Famously misunderstood wonder of the ancient world

This logic-defying 16th-century Tudor manor still stands to the delight and astonishment of onlookers.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

The beautiful baroque library of the Hapsburg empire.

This massive blockhead sculpture hides an entire library.

Hopefully inspecting his tin pan for little nuggets of gold.

Monument that stands 40 feet and weighs 1,000 pounds.

Three-story concrete ram with a permanent gift shop.

One of the first big sculptures anywhere in Australia.

Giant lamp houses the tourism information center.

A self-funded cemetery with a long list of inhabitants.

Come for the flowers, stay for the bats!

This historic observatory contains the world's oldest refracting lens telescope.

Taxidermy of the racing horse with a huge heart, who inspired hope in the Depression.