Architecture

First LEED-certified gas station in the United States.

At just six feet two inches deep, it is said by Guiness and Ripley to be the world’s narrowest freestanding office building.

Ruins of the Crusaders' headquarters.

An overlooked and unassuming engineering marvel.

An intriguing three-sided folly is a testament to one man's devotion to Catholicism and the number three.

World's largest crossword puzzle spans the side of a towerblock, its clues scattered throughout the city.

Fortified homes of highland warriors that are still in use today.

The biggest solar telescope in the world helps reveal the secrets of our sun.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A metal tree emits eerie, melodic notes on top of Lancashire's Crown Point.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

One of the last functioning antique elevators in Chicago.

Not to be confused with the iconic New York City skyscraper, this Chicago building is a vibrant hub for artists.

This Scandinavian island is the site of the first modern observatory.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

Hundreds of hidden passageways weave through the old quarters of Lyon.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.