The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

For patriotic Russians, this memorial honoring the Soviet soldiers who died liberating Berlin in 1945 is the most sacred location outside of Russia.

This monumental work of art symbolizes the coming together of a previously divided city.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

Tiny memorials honor individual victims of the Holocaust.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

One of downtown Berlin's last reminders of its Communist past.

From toys to kettles to scientific instruments, this German museum celebrates the beauty of 20th century design.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

Started as a kitchen garden, now the second largest botanical garden in the world.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

This small memorial honors a ferocious feline and local hero.

Inside a Scottish castle hangs the tattered remains of a flag with murky origins and supposed magic powers.

This ruined castle is said to be the legendary keep of a Viking princess.

The castle that provided the setting for much of 'Monty Python and the Holy Grail' is now a pilgrimage site for fans.

The Guinness Record holder as the "tallest cinema in the world" is a building with screens in almost every one of its 12 floors

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This vessel is the final ocean-going paddle steamer in the world.

The raised stones in the middle of this road through Culross are relics of a 17th-century class divide.

A 19th-century Neoclassical building now housing a Hindu temple represents modern-day Glasgow at its most multicultural.