You might recognise the name of this satellite town if you've ever flown to Barcelona, which is also interesting for us because the local council organise a monthly second-hand market in the middle of the town which is free to take part in.
Being the first Sunday of the month, we woke up with just enough time to get down there and see the end of the afternoon (the market starts at 11 and goes on til 14h). The Renfe is probably the best way to get there, it's about four blocks south of the station 'El Prat de Llobregat'.
There were about 100 stalls, all types of people involved, and the prices were all really quite cheap.
Along with all this jumble, there was a bike rental stall & they were selling tickets to an Artichoke & Jazz festival! I know.
There's nothing like this in central Barcelona, but we have been in touch with the organisers to see if they can give us some ideas/contacts/support to make our Flea more accessible.
Their blog is here, in case you need to know owt else.