I'll add another word of caution. Parking space concrete bumpers!! I had a terrible fall two years ago when I was at a wilderness area - in the parking lot - on a birding trip. I got out of the car while looking up through my binoculars watching eagles coming in. As I started to move forward to get a better view (still looking up) I stubbed my toe on the unnoticed bumper and launched myself onto the concrete sidewalk on the other side of the bumper.
Thankfully I didn't hit my head hard enough to lose consciousness but I did cut up my chin, put three teeth through my lower lip, sprained my left arm, including hand and wrist, up to the elbow and, worst of all, tore muscles, tendons, and damaged nerves in my calf resulting in compression syndrome in that lower leg. I also went into shock. Amazingly I didn't break anything. Fortunately I was with a friend who is an ICU nurse who got me sorted out and got me home.
Two years later all is well except for the leg which will plague me for the rest of my life. No more hiking or walking on hills, no stairs, no bicycling of any sort. Walking on flat surfaces is mostly OK but anything that causes me to have to raise my toe above my heel is out. I must say that the pain from that leg was the most excruciating I've ever had - worse than kidney stones, or any of the several major surgeries I've had. It was like the fire of a thousand scorpions every time I'd put any weight on it. It still aches and twitches and burns but not like in the beginning.
When I went to the doctor he said he sees more falls from encounters with parking space bumpers than from any other cause. His opinion was that they should be outlawed.
So the takeaway, as others have pointed out, is watch where you're stepping! I learned that lesson the hard way and I hope I'll never forget it.