The longest single stairway in San Francisco, climbing approximately 290 feet. To put that in perspective, that's almost a third of the way up to the highest point in San Francisco: The 928 foot summit of Mount Davidson.
It's another 130 feet just to get to the base of the stairway from the bottom of Warren Drive at 7th Avenue.
The only comparable stairway climbs are the Greenwich Street and Filbert Street steps up the east side of Telegraph Hill, and those consist of multiple separate stairways. The higher of the two (Greenwich Street) has a slightly shorter total climb of about 280 over its two stairways.

The top of the stairs reach an altitude of about 790 feet, also making this the highest elevation urban stairway in the city. Only the stairways in the parks atop the highest peaks in the city are higher.

This is one of my favorite stairways. Not just due to the challenging height, but for the climb into the Mount Sutro eucalyptus forest. This is best experienced on a day with low fog covering Mount Sutro.

Like all but one of the stairways Forest Knolls, the stairs are floating concrete steps with metal railings painted green. These stairways were all built around 1969, even though the Forest Knolls neighborhood was fully built out by the the early 1960s. Ashwood Lane is the exception; it was built earlier, probably when Clarendon Elementary School was built, and doesn't have the same design as the rest of the stairways in the neighborhood.