Gabion walls don't need any kind of drains because they are porous throughout. Gabions can be customized to make them more useful in public spaces. Gabions can be filled with any heavy material--diverse stones, metal artifacts, obtanium, etc.
Outdoor shower/water day for kids.Could easily be made with hollow box uprights, run the water tube through one and the top hollow box with a PVC tube that you drill holes in for the water to run out. Faux paint it to look like copper, really pretty easy.