Places meltingknight Wants to Go

At this faithfully preserved medina off the Moroccan tourist circuit you can walk through six centuries of history in one day.

Single runway interrupted by a busy road that cuts across its middle.

There was a top secret plan during World War II to seal a group of soldiers inside the rock.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

Helen Keller once broke ground on this historic center for the study of technologies to benefit the hearing impaired.

The first presidential bomb shelter was located in an old vault under the Treasury, connected to the White House via tunnel.

Decades before the scandal, this staircase on the river was a literal "water gate."

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

People escaping slavery may have hidden inside a corpse vault.

Largest Roman Catholic church in North America.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

Ride in 1960s style on the private luxury train Marshal Josip Tito used to travel around Yugoslavia.

This hilltop ruin is of the hundreds of stone columns built in tribute to the first German chancellor.

A long-buried ancient ruin unearthed right in the middle of the city.

In England, a barn-turned-wedding venue dates back to the 13th century.

The oldest surviving glass furnace cone in Western Europe.

Hundreds of iconic jazz records were made in this church-like space.

Songwriter Leon Russell transformed this church into a recording studio used by many legendary musicians.

The blinking light atop the iconic landmark has been sending secret messages for decades.

Oldest synagogue in the United States.