Architectureal fantasy quarter of Rome.

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

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

A Nesting Doll of Churches.

2300-year-old Roman road connecting the empire.

Stone memorial that's said to predict the death of the pope and the site of the Cadaver Synod.

The studio built by fascists in the hopes of "reviving the film industry" with the occasional propaganda film opportunity thrown in.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

This turn of the century masterpiece has a mysterious goaty interloper.

An overlooked and unassuming engineering marvel.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

A whimsical antique shop with a strong air of mystery, filled with items from ages, and what feels like worlds, past.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

Olfactory delights in San Francisco's Botanical Gardens.

A 140-year-old castle with underground caves hidden in San Francisco.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

The only theatre in the world constructed specifically for sound movement.

A geological oddity formed by two rivers carving out a mass of limestone on both sides.

A colossal sculptural lion built by the same man who designed the Statue of Liberty.

One of the world's most complex timepieces.

This disused boat elevator was saved from the scrap heap so that visitors could tour its rusting skeleton.