The Mission is two things layered on the same blocks: the oldest building in the city and the most painted walls in it. This walk threads the Spanish founding into the Mexican present, with a taqueria waiting at the end.
Start at Mission Dolores, the 1791 adobe that gave the district its name — the slim chapel survived the 1906 earthquake that took almost everything around it. Walk east to Clarion Alley, one block of constantly repainted, openly political murals, then drift down Valencia Street, the bookshop-and-coffee spine, letting the storefronts slow you. Cross to 24th Street, the Calle 24 corridor, where the Mission is most itself: panaderias, fruit stalls, Spanish on every awning. Turn into Balmy Alley, the oldest of the painted lanes, begun in the 1970s as Central American solidarity art and tended ever since.
End the way the neighbourhood does — a burrito on 24th, the rice-free kind if you're settling the argument the local way, and the 24th St Mission BART a few steps on.
