The control valves are mounted in a manifold that is enclosed in a box. There are boxes made for this purpose. Mine is underground, but they can be above ground. Usually the are located near the controller so there do not need to be extensive lengths of wire. Again using my system as an example, the controller is in the basement. The valve box is just outside the basement wall. The wires (you will need 6 for a 5 zone system) go through the basement wall above the ground level to help prevent leaks and into the valve box. The tricky part is the construction of the manifold so that it will fit in the box. I made my own originally, but hen the old valves began to fail, I hired an irrigation system installer to replace them. Installing the original was easier because I have a big hole to work in. (I was also about 25 years younger) The replacing was made difficult (for me at least) because now there are shrubs and a sidewalk to deal with. It was more than worth the price to hire it done.