Here’s a picture of a custom cave built as part of a workshop in 2006.
In 10 years there has been no noticeable wear on the rock surface but the colors have faded.
RicoRock Acrylic Stain will be used to add accent colors to make it look like new again; it will take two men two days to power wash, apply caulking in any concrete joints and recolor. There are two small areas of rust that will be chipped away and patched.
This project should last for many more decades, and it is easy to recolor from time to time. Ironically RicoRock lasts longer than waterfalls built with natural stone. It is tough to create water-tight structures with 10 or 20 tons of natural boulders, and many of those installations get abandoned after years of water loss.