wichita.edu
…the place on Mount Vulture where Christ appeared to him between the horns of a stag, newly discovered; and the church of the Blessed Virgin Mary, which, according to tradition, was built in the same place by Emperor Constantine the Great and solemnly consecrated by Pope St. Sylvester I—these have been diligently investigated, described, and illustrated…
https://www.wichita.edu/academics/fairmount_las/geology/wparcell/Kircher/HistoriaEustachio/historia1.php