At hagia sophia the entire roof structure rests on four massive:

Answer;

Piers

At hagia sophia the entire roof structure rests on four massive piers.

Explanation;

The Hagia Sophia is a domed monument built as a cathedral and is now a museum in Istanbul, Turkey. it is a domed monument originally built as a cathedral in Constantinople in the sixth century A. D. Whose entire roof structure rests on four massive piers.