This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

A planet-hunting astrograph built in the 1920s to seek out the so-called "Planet X" beyond Uranus.

A nature and cultural preserve named for its multitude of petroglyphs carved by the Northern Sinagua people.

A replica of the flagpole that gave a frontier town its name.

An open-air "garden" of mural art that changes weekly.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

These 2000 year old remains of a Roman aqueduct are hidden inside a hotel lobby.

This theater opened in 1998, but both the building and the puppeteers who perform there have a distinguished history.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

More than 300,000 historical artifacts from the famous music venue, from Duke Ellington's handwritten score to The Beatles' booking slip.

An annual extravaganza of Broadway theater memorabilia.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

There must be a pun in this haystack somewhere...

Cheap pizza and all of your naughty bedroom needs housed in a stunning example of Art Nouveau architecture.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

The only example of a Paris Métro sign in use at a subway station outside of the French capital. 

A massive Montreal stadium that has seen nothing but trouble since its inception.

Its columns were all carved from the same white oak tree.

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

Futuristic apartment blocks are the backdrop for Montreal surfers hangin' ten on the Habitat '67 standing wave.

Two thirds of this Montreal neon icon has survived to flash another day.

This 1967 experiment in modular architecture was designed to be a new model for urban living.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Ruins of the elaborate house where the enigmatic costume designer threw glamorous parties for New York's theatrical elite.