London’s oldest botanical garden is that rare thing: a hidden gem just metres from the Thames. Everything within its 300-year-old walls can be hired exclusively for large-scale occasions, or the constituent parts can be taken separately. Bordered by a rare confection of medicinal plants and herbs, the main Garden Lawn has room for a marquee. The more secluded Lower Lawn suits smaller events. Indoors, there’s an airy, upper-floor Gallery that looks out across the garden.