 The chalice is kept at the Basilica of San Isidoro in León, Spain, where historians say it has been since the 11th century.The publication of "The Kings of the Grail" in March 2014, which claims the chalice is the Holy Grail, led museum staff at the basilica to once withdraw the chalice from display, saying the crowds seeking to visit the museum were too large for it to handle.The museum now displays the chalice in a separate room in the tower alongside the old library.