So I've been doing a lot of research on how to build outdoor enclosure but haven't found a lot of specifics for marginated tortoises. I have a 4'x18' area in my backyard I am going to use, I live in a town home in San Diego so that's about all I can give him. He is only about 3" now. Any tips would be greatly appreciated, planning on starting in about 2 weeks. Thanks!