Portland has horse rings attached to the curbs in some old neighborhoods. The rings are often made of iron or brass, and they are remnants from the 1800s, when horses, and horse-drawn vehicles, provided the primary mode of transportation.
Searching for a geocache in this old neighborhood might help you discover one of these old horse rings! Might you see a mustang, a pinto, a bronco, or a colt?
Please replace so that a cache does not suffer equinocide.