A whimsical, but often overlooked clock in Park Avenue.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

For 20 years, local pumpkins have met their fate on the iron fence surrounding this Cobble Hill home.

The world's oldest hologram gallery and the labyrinthine laser laboratory of a holography pioneer.

Historical figures from New York City's Catholic community reside in Midtown.

This mysterious marker puzzles pedestrians and infuriates geographers.

This hidden oasis features a stunning view of the Hudson River and the Palisades from a castle-like museum.

Amid skyscrapers and traffic exists this unique aquatic ecosystem.

The best way to get a sneak peek at the movies.

A curious fountain that has no water and includes Satan, a crab, and 9 giraffes.

Along a busy beachfront strip you may hear Frank Sinatra singing from one boardwalk home.

Every year, the colorful murals of Montreal get a complete makeover.

A grand Gothic Revival basilica with stained glass depictions of Montreal's religious history has only one soul resting in its crypt.

Montreal's giant farmer's market is a foodie's best friend, especially in the winter months.

A reservoir of vintage pinball machines and arcade games for the nostalgic and thrill seeking.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

San Francisco's newly reopened hands-on science museum.

A psychedelic labyrinth on the San Francisco bay.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

Where dioramas can follow you home.

This awkward aquarium sculpture is one of the strangest statues in Chicago.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.