Turning night into day in Victorian-era Austin to thwart a serial killer.

Stunning Roman aqueduct used for 1900 years and still standing.

Erosion and time have created a naturally-formed water park.

The only swimming pool listed on the National Register of Historic Places is emptied and refilled each day with naturally filtered water.

A tower built by an emperor for an antelope.

A museum of alchemy and a basement laboratory all housed in an ancient building in a Gothic tower.

A 500-year-old series of tunnels long believed to be folkloric was uncovered beneath the streets of Puebla.

An Aztec snake god has taken the material form of an apartment complex.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

Hidden in the forest are the crumbling, graffiti-covered remains of the factory where most of Germany's explosives were produced during World War II.

A delightful but little-known public observatory and planetarium in Munich.