There are three Great Pyramids, and the Cheops is the largest one. It's somewhere over 540 feet tall. It's also thousands of years old. You can't see it in this photo, but there are people in the lower right hand corner. In the original print, you'd need a magnifying glass to tell that those little specs of color are full grown human beings.
Standing in front of the thing is an amazing experience. I pulled back to the widest possible setting on my 30-80 lens and still only captured a chunk of it. (Backing up any further would have dropped me off a hill, not in my plans for the day.)
The dark spot in the lower right is the original entrance. There's a smaller hole some distance further down where a few tourists are allowed to enter possibly the only humid place in the whole country not in the Nile River, at least at that hour of the day. If you want to climb through cramped tunnels to reach a little room, hey, you can do that.
Walking around the base of the pyramid is highly enlightening. It took me somewhere between 10 and 15 minutes. Luckily, the south and west sides were very quiet. From the south, you have a good view of the other two (smaller) pyramids. Small is a relative term, here. It's hard to convey an accurate sense of how large these things are. Suffice it to say that many of the individual blocks shown in the photograph are almost as tall as a full grown human being.