Episode 2 of City Walk journeys from Los Angeles to Boston. We take a closer look at something many of us take for granted - our own two feet. The series will take a look at the city wide cycling/walking extravaganza known as Ciclavia in Los Angeles, the pedestrian-friendly sidewalks and public transportation system of San Francisco, and Boston's string of urban parks known as the Emerald Necklace, as well as the newly completed Greenway in the heart of the city.