flea market 
noun
A street market selling second-hand goods.The Jam will also have a flea market where you can sell, buy and barter musical instruments, audiotapes, CDs and rock T-shirts....
- There was a flea market selling daft antiques - mainly old junk that it was difficult to imagine anyone buying.
- Garcia said US Customs began tracking Guthrie after undercover agents linked him to pirated discs being sold at a Mississippi flea market.