The heart of the church is formed by a central area with four adjoining square rooms, whose cruciform shape is reminiscent of domed Byzantine churches with the groundplan in the form of a cross. Parts of the walls of a former building – a Benedictine monastery mentioned in 9th century documents and destroyed in 1130 – were used in its construction. The west porch has a stone façade and a wide, three-stepped, flat-arched portal. The unique central tract can be accessed by a double, two-storeyed porch. From 1300 onwards the lower floor of the porch was used as a common room for pilgrims belonging to the Order of St John’s hospice, the upper level was a dormitory. The sacristy and residential house likewise belonged to the hospice. The largest Romanesque cycle of frescoes in the Vinschgau Valley, including the earliest portrayal of St Christopher in Tyrol, was executed in 1220/1230.