This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

A Jenga-style cylindrical tower of books that appears to go on forever.

A church of bones, decorated with 40,000 human skeletons.

The 953 windows undoubtedly make this the world's most beautiful screened porch.

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

An aluminum skeleton brings Chinese mythology to the French shore.

One Portuguese poet described this cape, the westernmost point in mainland Europe, as "where the land ends and the sea begins."

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

A breathtaking viewing platform over the Alps.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

One of the most well-preserved mammoth specimens in the world.

Strange rock formations tower above the river that snakes through this enchanting Icelandic canyon.

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

This medieval "painted village" is famous for its geometric facades.

This strategically-placed fountain creates the magnificent illusion of mustangs galloping across a river.

The "Mona Lisa" of funerary art.

Legend has it that any woman who kissed this statue would soon be married.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.

Steadily reminding Czechia of its past.

One of the famous Czech artist's lesser-known Prague installations appears to be a glowing fetus affixed to a drainpipe.

The final resting place of one of the most important figures in the world of tea.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

A floating cat sanctuary on an Amsterdam canal.