St Mary's Church (Mariakirken) was the royal chapel and had an important political role, as its provost from 1314 also was Chancellor of Norway. It was built originally in 1050 AD, but rebuilt and expanded several times. Final additions made in the 1300s. In the beginning of the 14th century, it was the third largest church in the country, and in the Middle Ages it was the royal chapel. The church was set on fire by Swedish forces in connection with an attack in 1523. After the Reformation, it was so dilapidated that it could not be repaired and was demolished in 1542.
Excavations were first conducted in 1867 under Nicolay Nicolaysen and later in the 1960s under the leadership of Håkon Christie. Remains of two people, deemed to be King Haakon V (1270-1319) and his Queen consort Euphemia of Rügen, were discovered during excavations of the ruins of the church and reinterred in the Royal Mausoleum in Akershus Castle.References:
The city walls of Avila were built in the 11th century to protect the citizens from the Moors. They have been well maintained throughout the centuries and are now a major tourist attraction as well as a UNESCO World Heritage Site. Visitors can walk around about half of the length of the walls.
The layout of the city is an even quadrilateral with a perimeter of 2,516 m. Its walls, which consist in part of stones already used in earlier constructions, have an average thickness of 3 m. Access to the city is afforded by nine gates of different periods; twin 20 m high towers, linked by a semi-circular arch, flank the oldest ones, Puerta de San Vicente and Puerta del Alcázar.