Great Pyramid/center of land masses

 

Well Israel IS roughly the center of the world.  A straight shot out by sea from Tel Aviv  through the Mediteranean gets you to the Americas; a straight shot down through the gulf of Aqaba from Eilat gets you to the Indian ocean; a straight shot east gets you to Asia; a straight shot north gets you to Europe; a straight shot East gets you to Africa.

It's the first place east of Cairo that gets regularly rained on from "above". So I go with Israel as the center of the world over lower Egypt which is fed from "below" by the Nile. 

 

Yeah, sure, in an area where the rock base would support the weight, close enough to the Nile and suitable quarries so that materials could be transported and in a convenient enough location for the workers. Oh, and close to the desert, since in Egyptian mythology, it was in the western desert that the dead went towards the afterlife... That's the amount of thinking that went into the location.

The Egyptians did not have the geographical knowledge to know where the Americas were, or just how large the Aerth was, especially by the 4th dynasty. In fact, at the time, they still thought they controlled most of the Earth...

 

Egyptian civilization was quite conservative.  Being isolated from other civilizations, the Egyptians could afford (until the time of the Hyksos) to consider their "world" timeless.  What was true 100 years before, was true in the present time.  Hence, Egyptian art and architexture was varied very little in 3000 years of its history.  Their own inscriptions show that they only knew the west as inhabited by "Libyans", the south by "Nubians", the east by "Asiatics", and the north by "the Great Green" (i.e. the Mediterranean) which had islands inhabited by "Cretans" and north of them, the Haunebu (probably Mycenaean Greeks).   Their world was always such.  It was only after the Hyksos literally "burst their bubble" that the Egyptians took more interest in the world, and took a more active effort to "control" more of it by conquest and thus became more familiar with more distant lands, but it still was not a "world-wide" interest.  As late as about the time of pharoah Necho I (Herodotus, 4.42), the Egyptians knew that Africa was surrounded by water (which the Phoenicians knew from about 1000 BC).