The hill of Montmartre became a place of popular pilgrimage after a chapel was erected by the people of Paris, around 475, where Saint Denis, the first bishop of Paris, was martyred. In the ninth century, the chapel, which had become ruined, was rebuilt. Archaeological excavations indicate that many Christians were buried in Montmartre. Their bones were gathered in a quarry on the side of the hill: the Martyrium or champ des morts.