Once close to extinction, there is no shortage of elephant seals on the beaches of Año Nuevo State Park.

It should come as no surprise that the world's largest artichoke lies in the town that calls itself the "Artichoke Center of the World."

With its peeling paint and faded sign, this theater-turned-recycling plant is a nostalgic relic of 1950s Americana.

The United States Capitol's former columns still stand.

Jesus' footprints and the first catacombs in the world.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

The final resting place of the poets Shelley and Keats.

2300-year-old Roman road connecting the empire.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

An alchemist's "magic door" stands in the middle of a Roman park.

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

Rome's semi-secret peephole vista is also a former Crusader stronghold.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

A fake medieval village in the middle of Turin.

The underground sanctuary of a mysterious ancient cult.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

The yawning maw of this pagan visage is said to bite off the hands of liars.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

A huge cathedral single-handedly constructed by one eccentric monk.