Those belting out show tunes in this West Village piano bar might not realize it marks the site where Thomas Paine died in 1809.

This giant subway sculpture celebrates the fruit that inspired the theory of gravity.

Sound travels strangely in this underground whispering gallery.

This gem from the industrial age helps visitors and residents alike traverse hilly Stockholm.

Sweden's oldest animated sign is still lighting up the skyline today.

When this 18th-century observatory's meridian was moved, it set Sweden's time back by 0.04 seconds.

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

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

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

This statue and park honor the Swedish chemist Jacob Berzelius, one of the founders of modern chemistry.

A heated statue pays tribute to one of Sweden's great actresses.

A wooden street sign is the last remnant of this 400-year-old alleyway.

Stockholm's narrowest alley is barely over two feet wide.

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

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

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

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

A golden plaque marks the site of the mysterious unsolved assassination of the former Swedish prime minister.

Medical museum that houses most notably the taxidermied remains of Vladimir Demikhov's famous two-headed dog experiment.

The oldest housing complex in Riga is a mini timeline of architectural trends.

The statue of a legendary giant who carried Christ and shouldered the world's sins.

This enigmatic artifact remained buried in a churchyard for years.

Flamboyant architecture from the turn of 20th century.

Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.