The only fair I do now is the Art Deco Fair at Eltham Palace.  This is an English Heritage site at Eltham.  Full details are on the Eltham Palace/English Heritage web site.  The fair takes place in May and September.

This year the fair takes place on   - 11th and 12 May 2013 and 7th and 8th September.

The entrance fee includes the Palace, the Medieval Hall and the Gardens.  The fair is in the Medieval Hall.