Built for an exposition in 1915, these horticultural displays have stood the test of time.

The world's largest outdoor organ is played weekly by one of just two civic organists in the U.S.

The massive machine creates cracking displays of indoor lightning.

Ice cream stand, snack bar, and time capsule of milk conveyance.

The world's largest piece of copyrighted artwork.

On a former island, this old fortification once used to protect the Boston Area and started Edgar Allan Poe in his military career.

The narrowest house in America is seven feet of pure spite.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

This bronze sculpture was inspired by a photograph of Martin Luther King Jr. and his wife embracing after he won the Nobel Peace Prize.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

Statue commemorating the use of ether in anesthesia.

This bridge was the birthplace of a unit of measurement based on a fraternity joke.

This impressive Boston holy house is the American mecca for Christian scientists.

Legend says this sacred tree was a gift from goddess Athena.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Go inside to really appreciate this 500-year-old technological masterpiece.

This crumbling medieval basilica once attracted pilgrims by the thousands to collect a miraculous dust that formed above the saint's tomb.

The ancient latrines of the Greeks, in all their public glory.

Carvings in Turkey's Marble Road may have directed ancient Romans to a hidden brothel.

A charming beach town in Turkey captures all the colors of the rainbow.

An enormous, inside-out glass globe built in 1935.

The oldest playground in America.