Many different valves here. Some are standpipes, for pumping water into a building in case of fire.
Some are hydrants.
Some are dual detector check assembly valves.
“Double Check Detector Assemblies prevent backflow of non-health hazard fire protection system substances from being pumped or siphoned into the potable water supply. It incorporates a meter to detect ground leaks and unauthorized illegal taps, greatly reducing annual water expenses. Its compact epoxy coated cast iron unibody and modular check design facilitate simple and easy installation and maintenance. ” OK.
Some are lushly landscaped.
Some are caged for their own protection.
This is a historic valve, near an old water tower in Palo Alto.
All the shapes, colors, configurations- hope you enjoy them.