At my elementary school the playground apparatus area was graced with these hard, black, rubber mats. They had virtually no give and got as hot as the asphalt.
All the apparatus was made out of steel and had no padding. We had a climbing cage, Olympic style rings, parallel bars (made of steel!), a couple of wide ladders-to-nowhere, and a an A-frame type structure made out of pipe that was almost impossible to climb on and get to the main beam which was too high up to jump to. Falling from it would have been quite injurious.
There was also a tether-ball pole right in the middle of it all but the staff never put a tether-ball on it so it was just a metal pole sticking out of the ground. And there was no slide.
On a hot day these things were unusable. On a wet day these things were unusable.
It was a play area designed by someone who was never a child, seen a child, knew what a child was, or cared to learn about children.
On the plus side it served quite well as a pirate island because there were not many tar-strips* that led to it, there were not many avenues to attack it as there were at the outside lunch tables or handball courts.
*You know when the asphalt cracks and the asphalt guys come out and patch it, it leaves tar-strip lines everywhere. Those you could walk on but the older asphalt was lava, obviously.