"an entire section of the San Jose flea market"
San Jose Flea Market
Creative Commons AttributionSan Jose Flea Market - Credit: LFL16, Flickr
The flea market at 1590 Berryessa Road, San Jose, is the largest open-air market in the US, with 4 million visitors per year.  It has 8 miles of aisles and 2000 vendors. 

The 120-acre site is due to be redeveloped as a housing estate from 2010, and an alternative site for the flea market is being sought.