The Petersfriedhof or St. Peter's Cemetery is - together with the burial site at Nonnberg Abbey - the oldest cemetery in Salzburg. It is one of Salzburg's most popular tourist attractions. Its origins date back to about 700, when the adjacent St. Peter's Abbey was established by Saint Rupert of Salzburg. The abbey's cemetery, probably at the site of an even earlier burial place, was first mentioned in an 1139 deed, the oldest tombstone dates to 1288. Closed in 1878, the site decayed until in 1930 the monks of St. Peter's successfully urged for the admission of new burials.
Carved into the rock of the Festungsberg there are catacombs that may stem from the Early Christian days of Severinus of Noricum during the Migration Period. They include two chapels: The Maximuskapelle and the Gertraudenkapelle, consecrated in 1178 under the Salzburg Archbishop Conrad of Wittelsbach and dedicated to the assassinated Archbishop Thomas Becket of Canterbury.
A second chapel, The Margarethenkapelle, (re-)built in 1491, occupies a cite in the center of the cemetery.
References:Kristiansten Fortress was built to protect the city against attack from the east. Construction was finished in 1685. General Johan Caspar von Cicignon, who was chief inspector of kuks fortifications, was responsible for the new town plan of Trondheim after the great fire of 18 April 1681. He also made the plans for the construction of Kristiansten Fortress.
The fortress was built during the period from 1682 to 1684 and strengthened to a complete defence fortification in 1691 by building an advanced post Kristiandsands bastion in the east and in 1695 with the now vanished Møllenberg skanse by the river Nidelven. These fortifications were encircled by a continuous palisade and thereby connected to the fortified city. In 1750 the fortress was modernized with new bastions and casemates to protect against mortar artillery.