Beaver Street Wall

The Beaver Street Wall is a sixty-foot-tall slab of chert tucked into the curve of a narrow park in the Corona Heights neighborhood. You can identify this wall by its glassy, smooth surface, which is marked by diagonal bands of red and tan that resemble a slice of bacon. This appearance is not the result of human craftsmanship, but of millions of years of geological pressure. Geologists classify the rock as a slickenside, a surface polished to a mirror-like finish by the friction of two massive rock formations grinding against each other along a fault line.