London has plenty of twenties, so let's visit some.
Only one London street has a twenty in its name, so let's start there. It's Twentyman Close and it's in Woodford.
Obviously it's a cul-de-sac, but I was hoping it'd have at least twenty houses so I could tell you all about Twenty Twentyman Close. No such luck, it's a brief two-lamppost affair and only five families call it home. Their houses are large modern detached affairs with prominent garages, four bedrooms and an L-shaped footprint. On the Essex sitcom scale it's not quite Birds of a Feather, but could well be Gavin and Stacey. For reasons I don't quite understand it's also a favoured location for postal staff to tie up their trolleys, two of the chunky red things, even when they're not around delivering. But most of all it's secluded, set well back behind the Edwardian properties on Monkhams Avenue, so clearly infill. And that's a hint that local history hereabouts is well above average.
Twentyman Close rubs up against the footprint of Monkhams House, a 19th century mansion on the slopes below Woodford Green. In 1864 it was sold to Henry Ford Barclay of banking fame, and on his death it passed to ArnoldHills, Chairman of the Thames Ironworks in Canning Town. Not only did their yard build the last warship on the Thames but it was also the birthplace of West Ham Football Club, which Arnold helped to found. He was also an FA Cup finalist (back in 1877 when all you needed was an Oxbridge education), and the first President of the London Vegetarian Society, and he had fourteen children. This is more local history than a suburban cul-de-sac normally supports.
In 1903 financial difficulties forced Arnold to sell the Monkhams estate to James Twentyman, a name which had to crop up in the story somewhere. James had made his fortune in China, but wasn't especially interested in the mansion so soon set about repaying his £60,300 investment by selling off the land as building plots. A prime middle class suburb emerged, extending all the way down to Woodford station, and after Twentyman's death even the big house was demolished to squeeze in an extra avenue. All that survives of Monkhams House is its Victorian stable block, which now runs down the eastern side of Twentyman Close - a much more interesting street than I first assumed. But it doesn't have a number 20, so that's a fail.