The opulent stations of Moscow's public transportation system are often compared to museums, and it's easy to see why. Join Matt and Rachel for a tour of Moscow's metro, and learn more about the city's brilliant stray dogs and Cold War secrets.

Home to the Louvre and the Eiffel Tower, Paris is one the world's most well-known cities. And beneath the extensive streets of Paris you'll find a fascinating, subterranean system with a story all its own. Tune in to learn more.

Located in New Zealand, Rotorua is one of the country's most popular tourist destinations -- and it's not hard to see why. In this episode, Rachel and Matt explore Rotorua's unique geothermal attractions (along with a bizarre activity known as 'zorbing').

Australia's Great Ocean Road stretches over 150 miles along the coastline, from Torquay to Warrnambool. Tune in to learn more about the breathtaking views and fascinating trivia surrounding one of Australia's most memorable roads.

Although the Colosseum of Rome is in ruins, it remains an impressive testament to the might of the Roman Empire. In this episode, Rachel and Matt delve into the fascinating story of one of the ancient world's most impressive structures.

Located on Hawaii's Maui island, the Haleakala National Park is home to one of the most unique landscapes on the planet. In this podcast, Rachel and Matt explore the breathtaking sights of this stark and stunning landscape. Tune in and learn more.

It's the 100th episode of Coolest Stuff, and Rachel and Matt have decided to commemorate the occasion with an episode on the greatest free party on Earth: Mardi Gras. Tune in and learn more in this podcast.

The transition between one year and the next is a momentous occasion that is celebrated all around the world in a variety of ways. In this episode, Matt and Rachel take a look at some of these New Year's traditions -- and bid a fond adieu to 2010.

Over the centuries, Christmas has acquired a lot of nifty traditions, from special foods to festive foliage. In this episode, Matt and Rachel pay homage to one of the most popular symbols of the season: the Christmas tree.

The Mekong River is often referred to as "mighty" for a very good reason: This massive river system winds its way through six countries in Southeast Asia and is full of giant creatures. Matt and Rachel take you cruising down the river in this episode.