There were 13 collection boxes, 13 tables, and 13 times the cohanim bowed in the Bais Hamikdash. The house of Rabban Gamlial and Rebbe Chananyah, the segan hachohanim, would bow down 14 times. This was done by the chamber of wood where they had a tradition that the Aron Hakodesh was buried.

Shikalim 6:2

There was a story that a cohein while he was doing his work noticed a difference in the flooring. He went to tell his friend but before he could finish, he died, proving that the aron was buried there.