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.
Gabion Walls - What They Are And How To Use Them In Your Landscape
Gavión de Grava de Piedra Molida Some innovative ideas on display at Appeltern Gardens, such as this hardware cloth metal mesh gabion-like fence, or perhaps it's a wall, partially filled with trap rock.
Wattle Fencing: A Cheap DIY Material for Modern Outdoor Spaces