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, selling 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.