San Francisco is a city of iconic bridges, impossibly steep hills and a famous nightlife scene. It is not, at least since legislation passed last year, a city of plastic bags. San Fran was the first metropolis in the nation to ban the use of plastic bags in grocery stores and pharmacies.

The bag law sets the tone for the rest of the city. Admittedly, San Francisco has always been a left-leaning place. Environmental consciousness has little problem fitting into the city’s day-to-day operations. But even notoriously non-eco-friendly businesses, like hotels, are taking steps in the green direction.

The Bay Area also boasts one of the country’s most extensive public transit systems as well as a strong bicycle culture.

Already green enough? Don’t forget the organic food scene and farmers’ markets. And at the center of it all is the newly completed California Academy of Sciences, one of the best examples of green design and architecture in the world (and one of the finest natural history museums as well).

Stay green

Boutique hotels abound in the Bay Area. Many of them have become more than merely hip places to lay your head. They're changing the way the hotel game is played. The unspoken axiom of comfort at any cost is still there, but inns like W San Francisco and the Orchard Hotel are realizing that most people welcome recycling bins and the use of nonchemical clearers in their rooms. The Hotel Carlton (Lower Knob Hill), already certified as a green business by the city, recently installed 105 solar panels on its roof. W is considering a similar energy strategy with wind turbines.

See green

The California Academy of Sciences is in Golden Gate Park, as it has been since 1853. But recently it received a new building. Actually, calling it a mere building doesn’t seem correct. It's a complex with exhibits that are blended together seamlessly. More than 40,000 animals can be found in the aquariums, the four-story indoor rainforest and a host of other exhibits. Add a planetarium to the mix and it seems hard to even label the venue a natural history museum, a zoo or even a science museum.

The building itself, designed by architect Renzo Piano, is as impressive as any of the exhibits. Its sustainable design, including a “living roof” with grass and soil, earned it a platinum ranking (54 points) using the Leadership in Energy and Environmental Design (LEED) rating system. Even more impressive was the fact that 90 percent of the new building was built using material that was recycled when the old academy complex, which consisted of 12 buildings, was demolished.

Eat green

Travelers who want to get a taste of the S.F. farmers' market scene could do worse than the Ferry Plaza Farmers Market (on the base of Main Street downtown). Operations are overseen by CUESA, the Center for Urban Education about Sustainable Agriculture. Area farmers, gardeners and craft makers sell their goods on Tuesdays and Saturdays, while local chefs are on hand to prepare the market’s version of fast food using fresh ingredients from the vendors.

Elsewhere, San Francisco is full of sushi. Minako Organic Japanese (2154 Mission St.) gives the fad an organic twist, catering to vegan customers as well as traditional sushi-lovers in search of something out of the ordinary. Alive! (1972 Lombard St.) features raw fare made with locally grown organic ingredients. Seating options here include a heated Zen garden.

Go green

The great thing about visiting San Francisco is that you'll rarely find an instance when stepping into a car is a necessity. Between the Bay Area Rapid Transit (BART) trains, the MUNI buses and light rail service and, yes, the occasional ride on a fabled cable car, it's possible to get just about anywhere in or around the Bay Area. San Fran is also a bicycle-friendly city. Some of the hills are monsters, but cyclists are at home on most major streets. The San Francisco Bicycle Coalition offers safety classes, group rides and route maps.

And the old tourist standbys are still there, too: Golden Gate Park, Chinatown, Castro, Telegraph Hill and Fisherman's Wharf. It's just that now, the city that's always been a great place to visit is growing greener by the day.