Here is a 40-minute walk that gives you a good leg workout, is light on the car traffic, and has the BEST views in Boulder — you can see every one of Boulder's peaks on this 2-mile (3-kilometer) urban hike.
Start at Greenleaf Park (Spruce and Folsom), or park at the Boulder Chamber of Commerce. Walk west to 23rd Street and turn right. Walk up the hill along 23rd Street until the street ends, then follow Panorama Avenue to the right until it loops around and becomes Balsam Drive. Pause to take in the good views.
Follow Balsam Drive west to Alpine Avenue, then turn left (south), and left again where it meets back up with Balsam. Continue on Balsam/Alpine until you reach the four-way stop where 19th meets 20th. Take a left on 20th, and another immediate left on Mesa Drive.
Follow Mesa Drive to the east until it ends at Lovers Hill Park. Take a right through the park and follow the path down to 22nd and Bluff. Walk south along 22nd back down to Spruce, turn left, and walk back to Greenleaf Park or the Boulder Chamber of Commerce.