Boulder sits in Boulder County, Colorado, a city beneath the Flatirons with a university, a famous pedestrian mall, and mountain trails in every direction. The Flatirons, dramatic sandstone slabs on the city's western edge, give Boulder its signature skyline, and Chautauqua Park offers trails and a historic auditorium at their base. The University of Colorado Boulder anchors the city, and Pearl Street Mall gathers shops, street performers, and restaurants downtown.