These clever people are using shipping containers, dumpsters and rubbish skips to create family pools at low cost. And you can take them with you if you move! Here are the pools they made --> theownerbuilderne.
Outside shower/bath why do I need an outdoor shower/bath? Because I have a metal smithing/garage/art studio and an outdoor garden which I like to keep my house clean when coming to & from these spots, so a shower would be nice, plus I have the space.