Munich(01 of10)
Open Image ModalThe progressive subway architecture of Munich\'s underground wonderland pushes the envelope. The U-bahn is made up of mod, technicolor stations with little evidence of human finagling (i.e. no pissed-on benches, trash or graffiti). While several stations are old as funk (as far back as the 1930s), most have been newly renovated to resemble kaleidoscope-like wonders. We like the Sankt-Quirin-Platz station best for its quirky mix of old and new.
Paris(02 of10)
Open Image ModalParis makes it easy for us \'mericans to navigate its subway system. As charming as public transportation gets, the romantic art nouveau architecture of the world\'s second-oldest subway system will put you in the mood for serious PDA on the comfy seats. Brush up on your French, and your train just might meet a tunnel.
Hong Kong(03 of10)
Open Image ModalOne of the most reliable subways in the world, the Hong Kong trains don\'t have operators. While we think there\'s a certain thrill to be on the fast track in a driver-less vehicle, the local population is a bit ho-hum about it. To make sure everyone is pleased with their human-less customer service, some stations are equipped with mood indicators.
Pyongyang(04 of10)
Open Image ModalYour mission, should you choose to accept it: sleuth out North Korea\'s subway system -- the best-kept subterranean secret in the world. At 150 meters deep, it was made to withstand nuclear attack and link covert underground military facilities. While tourist exploration is severely restricted (only two stations are open to the public), we heard a rogue reporter once snuck out of his guarded hotel to poke around the clandestine admin-only tunnels. There are no glitzy ads or art work to check out here; just the harsh faces of political leaders plastered to train walls.
Moscow(05 of10)
Open Image ModalThe Moskovsky Metropoliten has the largest ridership in the world, and that\'s just counting humans. Believe it or not, the stray dogs of Moscow have trained themselves to board and disembark (bark, bark) at stations of their choice because they have doggie jobs and families to get to, too. (No not really: They\'re looking for food.) They\'ve taken a cue from fellow riders to avoid eye contact and have a dog\'s sense to get off at the correct stop. Who could blame the bastards for wanting to check out the underground? Other marvels include the neoclassical station architecture, Komsomolskaya in particular.
Stockholm(06 of10)
Open Image ModalFinally, something to fill the void of Swedish-cool that ABBA and Bjorn Borg left behind -- the Tunnelbana, Stockholm\'s subway, isn\'t called the world\'s longest art gallery for nothing. Over 90% of its stations are adorned with mosaics, installations, reliefs and paintings by hundreds of artists badass enough to take it down a level. You can find shards of old buildings at the Kungsträdgården station or descend to the Odenplan station on a staircase resembling a grand piano. Several stations on the blue line feature exposed bedrock, painted in psychedelic colors and patterns that will likely derail your train schedule.
Tokyo(07 of10)
Open Image ModalToei Chikatetsu is Tokyo\'s futuristic subway system and the busiest metro in the world. What makes this metro so high tech? For starters: The extra busy Shibuya (she-boo-yah!) station, on the fourth floor of a trade center recently installed piezoelectric flooring that harnesses kinetic energy from the rush hour footfall and uses it to power lighting and other electronic equipment. Put that in your eco tech nerd cocktail and stir it.
Madrid(08 of10)
Open Image ModalOTP applauds your willingness to wear dirty clothes in order to save a little water. But get this, eco-warrior: the Madrid metro cleaning system recycles 80% of the water used down below. That\'s even a better rate than that drizzle bath you call a shower! In fact, the whole system was designed with the Kyoto Protocol in mind. If this doesn\'t stroke your eco\'nsceince, may the carbon footprint gods have mercy.
Beijing(09 of10)
Open Image ModalThis baby got a sexy makeover for the 2008 Olympics, much like the rest of Beijing. Never a country to skimp on fancy technology for its metropolitan centers, all trains are now bright and beautiful with sleek touch-screen maps, LCD televisions, underground cellphone reception and bilingual announcements. Forget the Forbidden City; we\'ll just hang down here.
New York City(10 of10)
Open Image ModalWhat do mutant rats and NYC natives have in common? The New York City subway runs 24/7, has an express train on almost every line and always gets you within a few blocks of your destination. What\'s more, every other ride features a free show -- whether you asked for it or not. With Michael Jackson moonwalking, drunk Polish men singing show tunes on the platform and gospel a capella groups parading through the car, you\'re bound to pass the next Bob Dylan during your commute. If you\'re lucky, you might even get kicked in the face by a pole-swinging break dancer.