The Western Greenway is located almost entirely inside the triangle bounded on the northeast by Concord Avenue in Lexington and Belmont, on the southeast by the MBTA commuter rail and the now-abandoned Mass Central Rail line, and to the west by Lexington Street in Waltham. To be sure, there has been a significant amount of development inside this triangle. But there are also significant swaths of green space.

The Mt Rainier Infinity Loop is an unusual challenge dreamed up by iconic Washington climber Ch