We have a beach house in the Outer Banks area of NC, about 1/4 mile back from the ocean. Right now the "landscaping" consists of nothing but sand and random beach grasses. There is no area where our two small dogs can run free at all. I want to fence in an area for them to practice agility training. The sand alone I think will not be good for their joints because it's too soft and uneven for landings, plus in the summer the pricker bushes spread and they would pick those up on their feet. I want a surface that has some give to it but will stay firm, as well. Would decomposed granite be a good idea? Or artificial turf?

I don't want to put in turf grass because that would require an irrigation system and mowing, which I don't want to do.

This area will be behind the house so will not be visible from the front. It doesn't have to look pretty necessarily, just be functional. Any ideas?