The basic model which inspired building most Holy Trinity columns is the "Pestsäule" or "Dreifaltigkeitssäule" ("Plague" or "Holy Trinity column") in the Grabenplatz, Vienna, built after the 1679 plague; in this monument the column has entirely disappeared in marble clouds and colossal saints, angels and putti. The era of these religious structures culminated with the outstanding Holy Trinity Column in Upper Square ("Horní náměstí") in Olomouc. This monument, built shortly after the plague which struck Moravia (nowadays in the Czech Republic) between 1714 and 1716, was exceptional because of its monumentality, rich decoration and unusual combination of sculptural material (stone and gilded copper). Its base was made so big that even a chapel was hidden inside. This column is the only one which has been individually inscribed on the UNESCO World Heritage List as "one of the most exceptional examples of the apogee of central European Baroque artistic expression".