Beneath the southern end of the Golden Gate Bridge is the “Gibraltar of the West Coast,” a fort built to protect the San Francisco Bay from naval attack.

The oldest alley in San Francisco is paved with a reminder of the city's original shoreline.

Wander down a side street dedicated to one of the members of the Beat Generation.

A collection of memorabilia from the Beat era in the back of a San Francisco bookstore.

The last used bookstore in Downtown San Francisco is one of the smallest bookstores just about anywhere.

Lombard Street may be more famous, but this is the real “crookedest street in the world.”

This colorful boulder serves as a canvas for political statements and artistic expression.

The miraculous hydrant that saved the Mission District in 1906.

This Alamo Square mansion is rumored to have hosted satanic rituals and other occult practices.

Russian history in San Francisco.

A four paneled, brightly multicolored mosaic adorns the side of this popular grocery store.

An unassuming grey box sitting on San Francisco's Pier 17 is a "sky diary" of the coastal city's temperamental weather.

The historic building's ornate stained glass fixture has survived the devastating 1906 earthquake, ensuing fires, and multiple redevelopment attempts.

The oldest church in Mantua was buried for centuries under the facades of other structures.

It took more than 300 years to build this church, which is home to two sacred vessels believed to hold the blood of Christ.

A room filled with frescos that make it seem like the walls are crumbling down while giants die in despair.

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

Bits and pieces from the ill-fated Donner Party's winter cabins.

This 19th-century museum inside of a lighthouse is only accessible during low tide.

Ghost town with a beer-drinking goat for mayor.

The world's only complete colossal squid specimen is on display at the Te Papa Museum.

This mundane post marks the old location of the city's main postal hub.

This Scottish graveyard is the final resting place of the man who inspired the character Ebenezer Scrooge.

Its appearance in "Game of Thrones" may spur on the long-awaited restoration of this medieval shipyard.