Do all older irrigation systems have a valve box buried somewhere in the yard?
No, this wasn’t a standard feature when sprinkler systems were first installed. Often, you’ll find the wires and valves buried in hard to find spots around the yard or near the foundation of the building or home. If a building doesn’t have a box, it’s a good idea to install one both as a protection for the valves and wires and also for easy access when repairs are needed.