San Francisco’s century-old Christmas Tree.

A tribute to the artist and activist who created the rainbow pride flag.

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

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

One of the smallest parks in San Francisco honors the legacy of the "Mother of Civil Rights in California."

These WWII-era murals were initially booed as a libelous portrayal of the American dream but have survived multiple attempts to have them destroyed.

Nestled in the heart of San Francisco’s bustling Financial District stands a unique homage to the Mayan and Beaux Arts.

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

A modern mechanical planetary system, part of a 10,000 year clock.

The largest whiskey stash on the West Coast survived the 1906 fires--but not without heroic effort.

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

With the touch of a button, you can read a randomly selected short story.

San Francisco's newly reopened hands-on science museum.

At the top of the hour, figures of the London department store's two co-founders emerge and bow to each other.

The commemorative stone column conceals a secret laboratory.

The Great Fire of London and the regulation of one-way streets both started in this alley.

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

A significant example of Czech cubist architecture—a style you won't find anywhere else in the world.

The world’s largest Masonic temple was saved by the White Stripes.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

This bridge was constructed from the rubble of the infamous Bastille.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.