The Apothecaries Garden in London was founded in 1673 (the oldest botanical garden in England - Oxford 1621).
Its proximity to the Thames creates a warmer microclimate. It is 3.8 acres of calm and wonder. The range of plants extraordinary, the care and devotion of volunteers swell the work force, but to my chagrin there is a shed nearest the river that is a real mess.
The labeling, too assiduously done, could do with a revamp: lettering, visibility, all is tended and in order but could be more so. It should be endowed in perpetuity by Chelsea's main landlord, the Cadogan Estate.
Take note, Charles, Lord Cadogan, your estate has done very well in SW3 for decades. The garden is not big and should be at least as well kept as say, the New York Botanical Garden in The Bronx.