How would you define Boulder? It probably isn't fair to call it Denver's smaller sibling, despite the two towns' geographic proximity. But it has enough of its own personality to not be filed under "overgrown suburb." Boulder is lots of things: a university town, a mecca for the environmentally conscious, a playground for climbers and cyclists, a hangout for hipsters, and a generally pleasant place to spend some time.

What passes for mainstream in Boulder may seem out-of-the-ordinary elsewhere. Bicyclists are a common sight, even during the colder months of the year. The city's bicycle culture is just one example of environmental friendliness, Boulder-style. Because it has the perfect geography for every type of outdoor activity (not involving saltwater, anyway), the conservation of natural areas isn't just a political issue; it's a necessity in the eyes of area residents. A 100-plus-mile greenbelt surrounds the city limits. After that, it's the foothills of the Rocky Mountains. Green inside, green outside.

Sleep green

Boulder's hotels are greener than many cities'. But there's such a thing as paying lip service to the environmental movement and then going about your business without making any changes. That's not an issue the Boulder Outlook Hotel has to worry about. The Outlook stands out of the green-hued pack. It was created in 2002 as a concept hotel with a goal of "zero waste." To that end, the Outlook has taken steps such as providing in-room recycle bins, operating a non-chlorine indoor pool, using compostable straws and cups in its restaurant, and supplementing its power use with wind energy. This might be a concept hotel, but the concepts work, as far as the environment is concerned.

Go green

Boulder has an impressive bus system for a small city. That's because it shares the network with Denver. It's possible to get just about anywhere by bus. Of course, because it's a smaller city, traveling by foot or pedal power is not only possible, but often more convenient than relying on motorized transit. At least, that's what many locals seem to think (judging by the number of cyclists plying the roadways). Traffic can be a bit hectic, especially around the University of Colorado, but the city has taken steps to protect peds and cyclists by creating numerous underpasses that allow people to avoid crossing busy streets.

Play green

Virtually every type of outdoor activity is available in or around the city. It's sometimes referred to as the "front door" of the Rockies. There are probably more serious climbers, mountain bikers, runners and backpackers per capita in Boulder than anywhere else in the country. With such a collection of outdoor enthusiasts, the conservation of natural spaces is bound to be high on the list of local priorities.

There are plenty of outfitters, such as Front Range Climbing Company , that offer guided climbing tours of area rocks. Experienced climbers will be able to hook into the scene easily. Colorado Mountain School offers a vast supply of information and instruction for novice and intermediate climbers who want to tackle ice and rock walls or trek above the tree line.

But there's no need to head for the hills to enjoy the Colorado outdoors. A seven-mile Boulder Creek Path runs right through downtown Boulder. Paths are paved for biking and Rollerblading, but once you're on the trail, you'd be forgiven for thinking you aren't in a city at all.

Of course, the greenbelt around the city offers more than 100 miles of trails for less crowded rides, jogs or walks.

Eat green

A restaurant simply known as The Kitchen has been using local ingredients, wind power and other sustainable practices to go from green to greener. A majority of the ingredients used in The Kitchen's kitchen are from local or organic producers. In addition, the restaurant uses biodegradable products and practices composting. Excess food and drink is given to staff at the end of each shift (not a bad place to work).

Other organic eateries include Leaf Restaurant , which features an eco-friendly wine list and organic martinis. Leaf uses seasonal ingredients when possible and features authentic veggie dishes from around the world, as well as some of the best faux-meat you are likely to come across.

Boulder isn't Denver's little sister. It's not a university town or a neo-hippie outpost. Let's just call it a great place to visit and a city where environmental issues and the conservation of natural spaces are always at the forefront.

Destination of the Week: Boulder, Colo.
Outdoors enthusiasts and eco-adventurists head for higher ground.