Inside this Krakow church, an explosion of psychedelic color.

Real bones which are said to have belonged to a Polish dragon.

This grubby wall is said to be one of the Earth's esoteric energy centers.

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

This antique thermometer honors the creator of the first universal temperature scale.

These rare statues are one of the few remaining material witnesses to Old Prussian culture.

A huge wooden clock that is so beautiful its creator was forcibly blinded.

Several 12th-century ruins can be found inside this historical market.

One of the world's largest amber altarpieces is housed within this reconstructed medieval church.

The hidden lair of an alchemist rediscovered in a 2002 flood.

The often-overlooked ruins of one of the first buildings designed by famous landscape architect Frederick Olmsted.

An old trolley bridge was converted into a breathtaking garden bursting with colorful flowers.

Over 50 whirling pools left behind from the glacial age.

Inspiring Herman Melville and Henry David Thoreau, Mount Greylock in western Massachusetts is the highest point in the state at 3,491 feet above sea level.

An arcade packed with a rotating collection of unique independent video games.

Love, knishes, and best wishes from this legendary Lower East Side bakery.

Salute the leader of the proletariat.

America's original house of worship for Spiritualism, the religious movement based on communing with the dead.

A temporary art piece to celebrate LGBTQ Pride is now a permanent part of Stockholm's traffic landscape.

This sublime architectural marvel is a rare example of an expressionist church.

These airport hangars are now a bustling shopping center with only hints of its past still lingering.

Small Easter eggs are hidden in the ventilation holes of the city's newest trains.

The scars of a remarkably organized public protest to save 13 elm trees are still visible in this Stockholm park.

An abstract representation of weather in Sweden.