the sheer weight of the rocks and built other extra ones under the seaa as seen in this video - built the pyramids so's to tilt the planet into flying safely towards marss to terrafor that place and the octopies they built land pyramids when the floods came told noah to build the boat save whoever and then they built carved the sphynx cos they are super advanced and they like art.
underground pyramids.
https://www.youtube.com/watch?v=QB8OXhvtOMY