Chelsea Physic Garden is one of London's most rewarding small gardens, founded by apothecaries in the 17th century to grow and study medicinal plants. High brick walls and the city's own warmth give it a sheltered microclimate, allowing plants to thrive here that would struggle elsewhere at this latitude.
The collection runs to thousands of species, with medicinal, edible, and useful plants arranged in a way that makes the garden feel part botany lesson, part hidden Chelsea retreat. It is much smaller than Kew, but far more intimate.