The Church of St Ambrose from the 13th century is a beautiful single-nave church with Romanesque-Gothic characteristics. It is located near the Upper City Gate where once the Benedictine Monastery of St Ambrose stood, whose original construction was mentioned as early as 941. The church got its present-day look when it was renovated in 1992.
The front side of the Church has characteristics of Romanesque architecture with a single entrance portal. Above the portal there is an opening in the form of a cross and above it a narrow Romanesque window.
The single-nave area was vaulted by a semi-cylindrical ceiling of tufa (a variety of limestone), and from the interior side it is reinforced by two belts. The remains in its foundation bear witness that the church had a semi-circular apse. The present-day rectangular apse 5 x 4 metres in size was built later. In the 15th century the Church of St Ambrose was renovated and the church area widened. It obtained its present-day form by being renovated again in 1992. The church is used for celebrating the Mass, and because it is very acoustic, also for occasional concerts.