It's not a particularly novel idea, but if you've got a handful of gravel laying around and half a tube of aquarium sealant, it's very easy to spruce up PVC pipe caves.
Here's one:
Here's another one in use:
It's pretty cheap and you can make them any color that you like.
Here's one:
Here's another one in use:
It's pretty cheap and you can make them any color that you like.


