Japanese keyhole shaped tombs were constructed in a variety of orientations so it is not clear which way up they are, or whether they have a right way up.
There are a number of theories as to the origin of their shape. One scholar (Kishimoto, 2013) claims that they may have been tombs to for two rulers, one sacred one secular, such as found described in the Wajinden. I have sugested that they might represent the female sex organ in an earlier post.
It also occurs to me that, possibly like stupa as discussed previously the shape of keyhole tombs might also represent the first person body view of our nose. In the image above I have superimposed a drawing of my nose on blurred Google maps image of the largest example found in Sakai City near Osaka which is 486 meters long including moat and surrounding park.
Those with a larger Aramid or Syrid nose would see more nose and a finer, possibly pendant shape like the tombs in Saudi Arabia.
In any event since our first person body view frames everything that we can see, including the night sky for instance, the nose(s) can be felt to be extremely large. If it were the case that we have personified our first person body views, and that our third person perceptions are as it were carried around inside them, then it would be a truth so terrifyingly big that it is difficult to convey in a sobre scientific way. It may be more meaningful to build massive keyhole shaped tombs, or say "the Kingdom of God is within you."
Kishimoto, N. (2013). Dual Kingship in the Kofun Period as Seen from the Keyhole Tombs. UrbanScope (electronic journal), 4, 1-21.