This may sound like the weirdest thing you have ever heard in your entire life, but did you know that the Great Pyramid of Egypt is actually a tomb constructed for Pharaoh Khufu and built in 2450 BC? This was a huge surprise for me:
In size, St. Peter's Cathedral could fit inside it. It's one of the oldest structures in the world (almost 5,000 years old) and the tallest structure until the Eiffel Tower was erected in 1889.
The second largest pyramid was built by Khufu's son Krafra as his tomb:
The white cap is actually the remains of the plaster that encased the pyramid. All the pyramids were covered completely in plaster and painted but only this one has it and it is only partially in tact at the top.
There were 3 pyramids built of significance during this time with the smaller one for Menkaure, the son of Khafra and the grandson of Khufu.
If you take a look at it from this angle, the second pyramid with the plastered top (middle one) looks higher, right? The reason is that King Krafa couldn't physically build a higher pyramid than his fathers' tomb. But he designed it on a higher ridge to intentionally make it look bigger. (History records that he wasn't all that great a king- just imagine his ego in trying to outdo his father).
For the Great Pyramid (really all of them), what intrigued me was how the Egyptians were able to build a structure of 3 million slabs of stone, each weighing well over a ton, in a 20 year timeframe. Mathematically, this would involve installing about 500 tonnes of stone every day and an average of about 20 of the blocks into place each hour, day and night for 20 years straight. One theory is that it was built by 100,000 men. I'm not saying it's impossible, but just imagine trying to manage that project...
The protector of the pyramids, the Great Sphinx of Giza, was built in the same timeframe. This statue was to protect the Kings for all time. Note that the body, paws and tail are a lion's form, representing strength:
Here's a picture of the Sphinx up close:
The site overall is absolutely breath-taking and you are in awe when walking the site in trying to comprehend how man could have built such magnificence. And how it has stood the test of time.