A rare surviving Victorian greenhouse designed specifically to house giant water lilies.

Crooked windswept pines give this old forest an enchanted and magical look.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

Sweden's "good old days" painstakingly re-created in a model village.

Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

Bring your hiking shoes, wool socks, and thermal underwear for a stay in these cozy forest huts.

The world's first ice hotel is still one of the most elaborate and beautiful.

Stockholm's deepest subway station is also a stunning ecological wonder.

The world's largest model of our planetary system.

This Stockholm light tower can be controlled by anyone with a smartphone.

The library's graceful rotunda is like a bibliophile's temple.

It houses the remains of a 17th-century version of the Titanic.

A series of modernist treehouse hotel rooms grace the outskirts of an Arctic forest.

A hidden bathhouse in one of Stockholm's oldest and busiest neighborhoods is open to anyone who can find it.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

This Jewish bakery, among the last in the region, sells legendary sweets from a century-old storefront.

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

At one of Berlin’s oldest churches, visitors can place mosaic tiles to help restore a medieval mural.

The original burial place of this preeminent 18th-century Jewish philosopher was razed by the Nazis.

Visitors can explore the role of mysticism throughout the ages inside this interactive museum of magic.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

All that's left of the quintessential "cabin in the woods."