An ancient instrument used to measure the waters of the Nile so Egyptian farmers would know whether to expect famine or flood.

An ancient city exhumed from the depths of the ocean.

Gigantic unfinished stupa and the world's 2nd largest bell.

Running since 1864, this clock has yet to be wound, one of the longest-running science experiments known.

One of the world's steepest streets seems to have houses sliding down it.

This Croatian computer club features such gaming relics as the infamous Virtual Boy and an 8-bit Pacman machine.

A musical instrument played by the sea.

Two towns are linked by an engineering marvel masquerading as a boring suspension bridge.

The site of Austria's biggest concentration camp now honors its victims.

Narrow-gauge railway with its own personal power grid.

Two nations form a rare four-sided border at the peak of a mountain, philosophical questions result.

This spire on an Austrian mountain is wrapped around a long spiral slide and has the world's tallest wooden observation deck.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

An exquisite Baroque church in Vienna's old town.

Resting in the middle of an Austrian river, this sci-fi "island" lets people cross in neon style.

The world's oldest known salt mine.

Double spiral staircases are not unheard of, but they are very rare.

The world's largest collection of intentionally useless inventions.

This series of underground chambers contains Europe's largest subterranean lake that is slowly drained each day.

Visitors dip into a variety of pools of what was once ice.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

Church organ in the Philippines constructed out of bamboo.