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

These "50 Fortresses" have been unearthed in the ancient oasis of Khwarezm.

This "tower of death" has acted as an observatory, a religious hub, and an executioner's lair.

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

Once a bustling fishing port, this semi-ghost town is now more than 90 miles away from the shore.

Light still pours into the ruins of this ancient Islamic observatory.

The Avenue of Mausolea is a series of grand palatial tombs.

The 28-foot granite map plots the locations of 40 theaters in New York City.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Commemorating the spot where the famous scientist fed his pigeons.

A dilapidated dock tells the story of Titanic's missed arrival.

Elevated freight railway turned wildly successful urban park.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Get a taste of Chamorro cuisine, family-style, at this popular restaurant.

A very classy 1920s-era bar right in Grand Central Station.

A dark patch of the ceiling at Grand Central Terminal which was not restored is still stained brown by tobacco.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

This subterranean oyster house has been the pearl of Grand Central Station since 1913.

Napa's oldest building is now a Mexican restaurant.

The only thing still moving in this town is the eponymous hot spring.

A cozy bookstore is tucked within an old gold mine shaft beneath the cafe and ice cream shop.

A volcanic cone that formed over 600 years ago.

A relic of the region's once booming timber industry.