A secret knock won’t get you in, and there’s no concealed button near the entrance, so if you want to gain entry to Barts, you’re going to have to hope that you pass muster with the person whose eyes appear to size you up from behind a sliding hatch on this bar’s main door. It’s all part of the fun, of course. Styled as a Prohibition-era speakeasy, you’ll find inside this intimate venue a wholly surprising riot of quirky spectacle – from ram- bling décor (think mounted deer heads and Marcel Duchamp-style Mona Lisa prints) to the dress-up box that allows more adventurous visitors to really party like it’s 1929.

Choose your cocktail from the absorbing Comic Book Menu, which tells the true story behind Uncle Barts, King Pin of the Chicago Underworld, while offering lavishly styled drinks encompassing house-made liqueurs and syrups, among other artisanal ingredients. And this being a favourite haunt of the Sloane set (unsurprisingly, given that behind Barts is royal pal Charlie Gilkes of Maggie’s, see Party), there’s copious amounts of bubbly on offer. If planning a weekend visit, do make a reservation, otherwise it could be an embarrassing case of that hatch slamming in your face.