I tried going into the Great Pyramid Of Giza, but I regret it. I'm not regretting coming to the Pyramids in Giza Egypt, only trying to go inside the Khufu Pyramid at 1:00 PM in the hot sun with crowds of people trying to come in and out on a tiny narrow ramp. If you are claustrophobic, do not attempt this.
The rest of my tour around the outside of the pyramids was amazing and a must see if you are travelling to Egypt.