Stuck in conference-room hell? Muni got you down? Well, grab your walkin' shoes: Within 20 minutes of downtown San Francisco is a gorgeous mountain trail enveloped in eucalyptus trees. San Bruno Mountain Park, just a heartbeat outside the city limits, offers eight trails through lush green trees, shrubs, grass, and generally nothing you'd see near Market Street. The paths range from about a half-mile to 2.5 miles long, with varying elevations up to 1,300 feet -- which is to say that you can opt for a leisurely walk or a strenuous hike. The Summit Loop, for example, offers tremendous views of the bay from atop the ridge, while the Bog Trail is designed for people with disabilities. The wildflower displays are spectacular, and you'll see an extraordinary number of plant and bird species along the paths. In fact, the place is home to more than 14 species of rare or endangered plants and at least four types of endangered butterfly. When you visit, you'll want to pack layers of clothing, since the weather can be wildly unpredictable. Then again, so can the weather in the Financial District, and it doesn't have butterflies.