A modern-day Polish explorer's collection of artifacts from around the world

Legend holds that this knife serves as a chilling reminder of the deadly rivalry between two local builder brothers.

A massive mammoth bone has been on display inside this church since the 18th century.

At night, this memorial illuminates a ghostly outline of a footbridge that connected two sections of the Warsaw Ghetto.

This colorful and quirky set of pegasus sculptures celebrate the works of poet Zbigniew Herbert.

This biographical museum honors the groundbreaking scientist at her birthplace in Warsaw.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

The former Nazi Germany concentration camp stands as a museum to remember this dark chapter in European history.

An underground city of salt.

Resting place and mausoleum of the founder and first president of Turkey.

This arch granting triumphal entrance into Antalya was designed to honor the emperor's visit.

The ancient latrines of the Greeks, in all their public glory.

Ancient serpentine sacrifice holder that has stood the test of time.

Ottoman-era houses lovingly preserved.

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

The best-preserved ancient theater in the world.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

This famous city eluded concrete detection until the early 2000's.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

Roman ruins top white travertine terraces formed by ancient hot springs.