Entering through the red sandstone portal, visitors are brought through a modern glass-faced entrance area into a beautiful church with a magnificent Rococo interior. St. Augustine's is situated in the heart of the city centre. It suffered only minor damage during the Second World War and is therefore one of the few churches in the region still featuring a virtually intact interior from the period of construction. From 1260 to 1802, the mendicant order of Augustinian Hermits had a monastery at Augustinerstrasse. Between 1768 and 1772, a new monastery with a one-aisled church was built. In 1805, the monastery was converted into the diocesan seminary.
The rich ornamentation of the church reflects the fact that its construction was generously supported by patrons. After all, the Elector would not have been impressed by a small village church in his residential city. The façade is in the vibrant Baroque style typical for the Rhine-Main region and features a Coronation of the Virgin by the sculptor Nikolaus Binterim from Mainz.
Inside the church, the painter Johann Baptist Enderle from Donauwörth glorified the life of the Father of the Church Augustine in large, bright ceiling frescos. In 1773, Johann Heinrich Stumm built the divided organ with the centre window. It is one of the few surviving instruments designed by a member of the Stumm dynasty of organ builders. In a niche between the south altars, a lime wood sculpture dating from 1420 catches the eye of visitors. It depicts Mary with the Child Jesus playing and smiling – an unusually serene work of Gothic art, assigned to the "soft style". The venerated miraculous image was rescued from the burning Church of Our Lady in 1793. The high altar is an iconographic rarity: It depicts God the Father who, at the death of Christ, has "Mankind's Book of Sins" torn up by a putto.