Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

A Christian monastery stands on what was once a holy Incan temple.

A painting in the historic Cathedral Basilica depicts Jesus and his disciples dining on a traditional Peruvian menu.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.

Surrounded by a verdant garden and a backdrop of ivy, a monument to beloved poet Khalil Gibran stands outside of the Lebanese embassy.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

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

The school tested mustard gas for the U.S. Army during World War I.

The National Park Service’s best-kept secret with views that rival any in D.C.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

An overlooked memorial honoring the local Washington residents who died in World War I.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

Look closely and you’ll notice that the color changes a third of the way up the tower.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

A shining treasure trove of fine Mexican silver dating back to the 15th century.

An ode to a chess-loving diplomat.

Twelve natural mummies are displayed in the crypt of this former monastery school.

An extravagant 18th-century fountain built with bits of broken ceramic.

The famous artist couple lived and worked here, in two different houses connected by a bridge.

This monument is a stark reminder of the horrors of the Zanzibar slave trade.