This historic square in Nepal is home to temples dating back to the third century.

The mysterious empty cupola behind the monumental arch points to an ancient prophecy of Delhi.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

One of the most easily accessible examples of the rare 1960s UFO houses.

An artificial date palm stands as a memorial to Warsaw's Jewish community.

The giant statue and its model solar system honor the native Pole who declared that the Earth revolves around the Sun.

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.

The naturally mummified body of a peasant girl saint.

Stockholm's narrowest alley is barely over two feet wide.

This floating sculpture of ice is a poignant reminder of nature's power.

The first memorial dedicated solely to the Black troops who fought for the Union.

For 60 years, the academy had no permanent location until members voted Washington D.C. as its forever home.

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

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

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

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

A secret greenspace hides atop a Capitol parking garage.

One of the last remaining movie theatres in the country that features a rear-projection system.

A 300-kilogram egg sculpture that embodied a neighborhood revival.

Plaques celebrating Lithuanian writers freckle a wall of this picture-perfect path.

This magnificent Art Deco church is a reflection of Lithuania’s turbulent history.

Where a Japanese government official issued transit visas to Jews fleeing from Nazi-occupied Poland.

This striking structure is the Socialist-modernist centerpiece of a former Soviet spa resort.