There's no title and no artist cited for this chill looking whale tucked onto the fading back of a Visitacion Valley building at the spot where Delta Street temporarily becomes a footpath. His one eye peers at you down on the street corner, knowing all and seeing all but keeping it all to himself.

A mosaic rather than a mural, this one on the side of the Chase Bank dates to 1977 and is the work of two California artists and one British one. There are five pairs of working people, each representing one of the agricultural hubs of the Pacific, from Japan to California.

Sirron Norris'd “El Toreador” isn't exactly hidden, of course. But its prominent placement right up over the door of the El Toreador restaurant might lead you to overlook it as signage the first time you walk by. Norris' work in West Portal turned out to be even more prominent than he'd like in 2015, when he discovered that local realtors were using it sans permission in a calendar.

Pac Heights would scarcely have a mural presence at all if not for Las Vegas-based artist Dray's oddly titled “David Chiu Mayoral Mural.” The building was briefly the headquarters of Chiu's mayoral bid in 2011, of which this piece is the only lasting legacy.

San Francisco artist Leon Loucheur usually specializes in "deconstructed" animals, but fortunately kept his bird on this Argonne Elementary School stairwell more or less intact, presumably for the benefit of the kids.

In 1974, artist John Wehrle was teaching art classes as the de Young for the "princely sum of $648 per month." He and John Rumply decorated the museum's old facade with several painted panels like this one. A few years on, "Positively Fourth" migrated to Fort Mason, and sadly is no longer with us.

The WPA murals at the Beach Chalet are quite famous. Even so, thousands of people visit the site every year without actually going on to take a look at them, or even overlook the scenes of everyday life circa the Great Depression when they do.

This one's a collaboration between Precita Eyes and Caltrans, and yet it's largely hidden underneath a freeway in Glen Park. A hidden treasure.

Another Lochter piece, this tattooed shark cruises along parallel to the freeway on a stretch of Sunnyside wall.

This was the first of three Diego Rivera murals in San Francisco (the other two are at City College and the SF Arts Institute), and, in a way, the weirdest, painted as it was inside what was at the time a stock exchange and is now a dining club for one percenters. It's not really forgotten, of course, and yet, many locals have never popped into the building to actually see it.