The Panthéon (Rarely Pantheum. This rare usage appears in Pliny's Natural History (XXXVI.38) in describing this edifice: Agrippae Pantheum decoravit Diogenes Atheniensis; in columnis templi eius Caryatides probantur inter pauca operum, sicut in fastigio posita signa, sed propter altitudinem loci (...) (from Wikipedia)