Once a regular haunt for the Duke of Wellington, 116 Pall Mall is now the Regency home of the Institute of Directors. A grand staircase – with viewing balcony – leads into five floors of versatile function rooms: look out for the dual-aspect Waterloo room’s gold-leaf-on-linen wallpaper. The IoD Academy, a newly launched training facility, suits business-first events. The Wine Bar, in the original vaulted cellars, is the place to unwind.