In the Royal Court Urban Area, the colossal Sacred Summit isn't even the full size of the Mother Nest; it's merely the portion of its body exposed above ground. Beneath the surface, at least three-quarters of its massive form remains hidden!
If this weren't the case, the so-called Sacred Summit wouldn't be able to host an entire city—the weight of all this infrastructure depends entirely on the Mother Nest's enormous body as its foundation.
Given the scale of its body, the Mother Nest rarely moves. Movement itself causes the earth to shake and mountains to tremble, and it isn't exactly quick either. Back when it relocated from the United District to the Royal Court, it took nearly a full week, just barely faster than some cars.