Commonwealth Avenue runs from the Boston Public Garden out beyond the confines of Boston. This is the longest street in the city of Boston. The blocks that run through the Back Bay neighborhood are part of 'the Emerald Necklace" - the 6 mile long set of parks designed by Frederick Law Olmsted in the 1880s. It's featured every year as part of the Boston Marathon and both Boston University and Boston College are stretched along "Comm Ave." Commonwealth Avenue is also known for the beauty of it's natural "walking mall". This is the tree canopied, brownstone surrounded, and park bench studded wide sidewalk that slithers up a large portion of Comm Ave.