Light still pours into the ruins of this ancient Islamic observatory.

The haunting ruins of a military fortress turned astronomical observatory sit on a Sarajevo mountaintop.

The Chilean mountain is freckled with (relatively) small European telescopes.

This futuristic observatory at the top of the Pyrénées offers unrivaled views.

Erected in 1803, it is the first astronomical observatory that was built in the Americas.

One of the world's most advanced radio observatories sprawls across the Atacama Desert.

An American ghost town hides along a side street in Scotland's capital.

Legends of treasure and spirits flow from this this fairy tale-like oasis.

In 1787, a group of delegates met at this very spot to drink, be merry, and ratify the Constitution of the United States.

Remnants of the most densely packed city in world history, that thrived on anarchy for 30 years.

An 18th-century estate owner thought these cottages were an eyesore, so he artfully disguised them as a church.

A mountain of conch shells created by centuries of fishermen.

It was an experiment to prove that glacial boulders and rocks can be used in constructions and dwelling.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

The century-old remains of an abandoned farm town in eastern Washington.

This shop specializes in oddities and Victorian-inspired wonders.

This contorting sculpture is the tallest in San Francisco.

This tall and trim architectural oddity is one of the skinniest buildings in San Francisco.

A garden oasis filled with flowers mentioned in the works of William Shakespeare.

A walk down memory lane in the heart of one of San Francisco's most notorious neighborhoods.

This 19th-century church is now a popular roller rink.

An overlooked and unassuming engineering marvel.

The restored and active Victorian-era final resting place of San Francisco.

San Francisco's oldest surviving monument and meeting place for 1906 survivors.