This spot along the 23.5 degree north parallel marks the northern boundary of the tropics.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

The highest dunes in California are the most likely place in the area to hear the Singing Sands.

A massive hydrovolcanic explosion left a half-mile wide crater in Death Valley.

The rocks in this arid basin leave trails of movement behind them.

Travelers leave tea kettles in a remote part of Death Valley as part of a mysterious, decades-old tradition.

This desert oddity hides in plain sight thanks to a cartographic error and a desert explorer with a punny sense of humor.

A hard-to-reach oasis in a desolate corner of Death Valley National Park.

Built entirely of interlocking pieces, construction of this Chinese Muslim house of worship required zero nails.

The heartbeat of modern Uzbekistan’s thriving market culture.

The controversial final resting place of the equally controversial first president of Turkmenistan.

Ancient barriers wrap around what was once an important stop along the Silk Road.

Open day and night, a church with three pews and Bibles.

The northernmost international land border crossing in the United States.

An Alaska livestock farm devotes itself to harvesting wool from creatures that once ran with mammoths and sabertooth tigers.

North America's first frozen mummified remains of an ice age steppe bison, the 36,000 year-old mummy named "Blue Babe."

A rare chance to get up close and personal with a 13-mile ribbon of ice near downtown Juneau.

More than 100 Hindu temples are slowly being swallowed by the forest.

This tourist village in Nairobi celebrates the traditional lifestyles and customs of Kenyan tribes.

Known as "The People's Park," this verdant oasis is home to elephants and villagers alike.

The ruins of an ancient Zoroastrian Tower of Silence believed to be the earliest example of the traditional funerary practice.

The celebrity luchadores of La Paz are tough ladies in traditional petticoats and braids.

The first declared National Monument in the United States.

Quite simply the largest tree in the world (by volume).