The Basilica Hilariana was a sanctuary[1] dedicated by the cult of Cybele on the Caelian Hill in Rome, Italy, in the name of a certain M. Poplicius Hilarus and identified by an inscription in Latin: collegium dendrophorum Matris deum magnae et Attidis, lit. 'college of dendrophori of the Great Mother Goddess and of Attis'.[2] Its vestibule was discovered in 1889 during the construction of Rome's military hospital on the Caelian Hill, the Policlinico militare Celio, along with a mosaic floor and the inscription quoted above. However, its floor plan is unknown.[3][4]