Sorry Muppet but cats are not that particular about where they go as long as they can cover it up when they have finished.

I have a gravel area and the cats dont use that but they do use the bark

I have gravel they use that and the bark on the borders, I'm afraid..

I use a strong scented fluid - zoflora etc ( I know some people who use jeyes! ) and soak used dry teabags or coffee pods in the fluid and place around the border, they don't see to like the smell. That works for my bark and borders...

I am still working on the gravel, as it is right outside my front door.

Use pebbles and not gravel, they hate those, too large for them to push about.

Sorry mine is pebbles oops!

Good decision, Drc, not to use gravel.

It was it still looks great

And doesn't blow everywhere if you use a leafblower, again, unlike gravel

I dont get leaves down there - its at the side of the house and has 3 very large Junipers in it.

Muppet,
If you do a site search on cats you'll find many answers to this question over the years GOY's been going. It crops up time and time again, just like the cat doo-doo unfortunately.