The parks vary. Some are city-managed, some are maintained by neighborhood nonprofits, some seem to exist through a kind of collective will that nobody has formally organized. What they share is smallness — we're talking parcels where a dozen people constitute a crowd — and a particular quality of use that larger parks don't quite replicate. People sit close to each other here. There's no room to spread out, so you don't.

On a recent weekday afternoon, three older men were playing cards at a folding table in one of the lots off Turk, shaded by a jacaranda that had grown well past what the original planting probably intended. A woman nearby was video-calling someone, holding her phone up to show the tree. None of this was remarkable to anyone present, which is the point.

The Tenderloin has some of the highest population density in the city and among the lowest ratios of parkland per resident. The postage-stamp lots don't fix that math, but they redistribute it in granular ways — putting a bench where a vacant lot used to catch wind and wrappers, putting a planter where a chain-link fence used to close a gap between buildings.

Some of the lots have been improved in recent years through DPW partnership programs; others predate any formal program by decades. The city's interest in them has waxed and waned.

Anyone walking Leavenworth or Turk or Willow this week would still see them: small, improbably green, in active use, the planter boxes just beginning their late-summer dry-out.