I think it will be a bit bumpy but possible. There are no paved sidewalks or roads.
It is accessible for a wheel chair when I went but the walkway is a dirt walkway not paved. So it might be a little bumpy. But yes when I was there a wheel chair could stay with the tour. After talking to my girlfriend we actually remember there was a person with a wheel chair there when we were there.
Yes the ground is hard packed dirt. If you stay with your guide on the main walk ways you will be fine!
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