Every year I love to go & have a nose at other people's gardens open under the Yellow Book scheme. Have just got my booklets for London & Surrey, being too mean to buy the full book, & a first for both areas is that they each have an allotment site open. This is a first, although it may have happened in other areas. I'll certainly try to get to see the London ones - compare what we have!
Whereabouts in London Beejay? Might have a nose myself ;D
Not too far from you SMP - Short Lots Allotments, Watcombe Cottages, Kew (NE side of Kew Green) Sun July 16, 2-5pm.