Where is the original wooden model of the dome of saint peter's basilica (created by michelangelo) located?

The Vatican

Explanation:

Michelangelo was made chief architect at Saint Peter's Basilica in 1546. He took charge of the church's construction making his own changes while honoring Bramante's original design. Michelangelo ultimately became responsible for the altar end of the building on the exterior and for the final form of its famous dome which included a ribbed design used from Florence. The original wooden model he worked from can now be found at the Vatican.