A mesmerizing disco ball-like sculpture along the Sacramento River Walk.

A lighthouse built to save lives that took quite a few with its treacherous location.

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

Canyon walls shrouded in ferns.

Humboldt's human-powered sculptures race across land and sea for days on end in a wacky quest for dominance.

A simple plaque remembers a California island massacre that claimed more than 100 lives.

A crumbling wizard is one of the final reminders of a roadside Middle Earth.

This Taoist temple is the oldest continuously used Chinese temple in California.

A Tibetan Temple and Buddhist organization just off the beaten path in Northern California.

The long, arduous journey of the stones of the Abbey of New Clairvaux.

This ultra-modern California span is actually a titanic solar clock in disguise built by famed architect Santiago Calatrava.

Neither Spanish settlers nor anyone since has been able to tell who built these strange California rock walls.

This lesser known Hearst estate is a fairytale village built from the stolen bones of historic European buildings.

Long abandoned underground complex to keep royals safe from a nuclear war that never came.

Accessible only at low tide, the deserted island is dotted with World War II ruins.

The abandoned transportation hub hides within the Glasgow attraction it once served.

The small Scottish townhouse where the "Father of the National Parks" was born.

This charming old building's loose connection with the Scottish Reformer is what saved it from demolition after it split apart.

The dance of this huge clock is a magnificent and eerie commentary on good and evil in the history of humankind.

This unassuming shed was the stage for a monumental event in British history.

Glasgow's memorial to the International Brigade volunteers from Great Britain who fought and died in the Spanish Civil War.

This historic pub has maintained much of its 1906 decor, including a small sequestered room for women, where orders were slipped through a tiny window.

One of Edinburgh's oldest pubs hides a 19th-century skittles alley in the back.

The oldest house in Glasgow is now a museum dedicated to the city's medieval history.