Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

A natural dome made of volcanic glass in Inyo National Forest.

Come for the pizza, stay for a performance on the world's largest theater pipe organ.

This old selenite mine is dotted with tiny crystals that make it shimmer like it's covered in glitter.

The largest copper mine in Arizona, this enormous open pit emerges from the hills like an alien landscape.

A nature and cultural preserve named for its multitude of petroglyphs carved by the Northern Sinagua people.

The cinder cone volcano with a less than complimentary name.

Witnessing the might of this dessert-colored desert waterfall is a rare, powerful treat.

These free-roaming horses were once destined to disappear from the land.

The world's largest rose bush has literally outgrown the pioneer museum it was planted behind.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

Venue for strange sideshow displays and musical acts.

An exotic wildlife habitat right off The Strip.

This dramatic sea spire is home to the world's rarest insect and is part of the lost continent of Zealandia.

In paradise, feral pigs have claimed an island all to themselves.

James Turrell's total color immersion art installation, hidden on the top floor of a luxury handbag shop.

Crypt mausoleum in cathedral's basement contains relics of third century Roman martyr, Saint Vibiana.

Panorama exhibition hall in old silent theater with a beautiful backyard garden.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

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

The only visible piece of San Francisco's most famous shipwreck.

The tea room that pushed the boundaries of adorable straight into...we can't find the words.

Its buzzing collection honors vibrator history.

San Francisco's oldest operating hotel, with a Victorian atmosphere and a "haunted" fourth floor.