Forget, for a minute, the Singapore you usually hear about in the media. Yes, in the past, the city-state has been known for its harsh drug laws, censorship, gleaming shopping malls and steep fines for spitting gum on the sidewalk.

Think of this Singapore instead: large swaths of green, far-reaching public transit and breathable air (absent in all other major Southeast Asian metropolises).

Is the Lion City an eco-friendly utopia? By no means, at least not yet. But if you're looking for a green destination (both in color and catchphrase), you'll find a lot of positives in Singapore.

Step off the plane and into the green

Changi Airport is recognized as a world-class facility, consistently ranking among the top three airports in the world in the prestigious Skytrax World Airport Awards. Six open-air gardens have been incorporated into the airport's design. Sure, they're nestled among designer boutiques and duty-free shopping areas, but they show that Changi has recognized the need for green — not just for environmental friendliness, but also for the mindset of passengers, many of whom are about to begin a long-haul flight or have just disembarked from one.

Balance of urban and natural

Singapore is one of the only cities in the world to have primary rainforest within its boundaries. Bukit Timah Nature Reserve spreads 164 hectares (two-thirds of a square mile) and contains a ridiculous amount of natural, tropical plant life. Its well-marked trails warrant at least a three-hour excursion. It's a perfect break from Singapore's understated urbanness.

Bukit Timah is just one of the city's many parks and gardens, some of which aren't even above water. Chek Jawa Marine Park features a coastal forest, mangroves, sand bars and a seagrass lagoon, and tours are conducted by local naturalists. Like Bukit, it's free to visit, though prebooking a tour is required.

There are also other easily accessible parks in Singapore, including the Singapore Botanic Gardens (orchids anyone?), Fort Canning Park (sculptures anyone?) and a host of others. Though you might find green spaces lacking on the famed Orchard Road, compared with other cities in the region, Singapore is almost impossibly green.

Public transit that works

Singapore's government has championed the use of public transit instead of private automobiles. There are still roads and expressways in the city, but the far-reaching train and bus system means it's possible to get anywhere without having to hail a taxi. In addition, this is the least baffling public transit system in Southeast Asia. Vehicles run on time, and signs, maps and fare details are in English. The EZ-pass card, available at all stations, pays for both bus and train fares.

Tourists can get an $8 per day pass at central train stations good for unlimited rides on the city's bus, train and light rail systems. Depending on how much you plan to move around, this could turn out to be quite a deal.

If you do choose to rely on taxis, your conscience can also rest easy. Many services are currently experimenting with compressed natural gas instead of gasoline.

Landfill with a light footprint

Singapore is the center for some other ambitious eco-friendly projects, as well. One of the most impressive is the island of Semakau, site of a large landfill. Rather than adopting an "out-of-sight, out-of-mind" perspective, Singapore paid special attention to the animal and plant life on Semakau during construction of the landfill. Mangroves and coral reefs still thrive. While urbanization has made certain types of wildlife scarce inside the city-state, Semakau's ecosystem remains largely untouched. Visitors can only enter with a guided group on nature walks or bird-watching tours.

Hotels get on the eco-bandwagon

The city's hotels were late entrants into the environmental game. Until recently, many guests were wary of eco-initiatives, suspecting that hotels were merely trying to save money, not the environment. But many hotels, like M Singapore, are getting into the green spirit now by conserving energy with LED lights, alternatives to air conditioning (a big energy eater in steamy Singapore) and new recycling strategies.

The National University of Singapore seems to be spearheading the green revolution among the city-state's businesses. It acts as a kind of a watchdog, conducting studies on energy efficiency and outing hotels who pay lip service to the environmental movement but whose actions are only skin deep.

It adds up

Singapore is synonymous with skylines and shopping. But the city is Southeast Asia's greenest, both in terms of natural preservation and sustainable practices.