Not the place to go if you’re looking for the lowest deal (it’s in Mayfair), but it’s definitely a source for variety. There are some 200 vendors, many experts registered in the official antiques societies, split among two buildings, and they sell everything from Victorian jewelry to toys to strange bric-a-brac and collectible silverware. Weekdays are best. Head into the basement of the Mews building to see the River Tyburn, which was buried by 18th-century redevelopment but now feeds into Grays’ goldfish trough.