St. Clement's Church or Klemet's Church was one of the Roman Catholic parish churches of the old Oslo. It was a stone church with a tower, and it was one of the very few churches we know with the double-nave floor plan. Along the middle axis of the choir there were three powerful pillars that held the roof. The church went out of use after the Protestant Reformation, and expect it rather quickly was in ruins.
The church was exposed and examined through excavation by arcitect Johan Adolf Gerhard Fischer in 1921. Then remained for years unnoticed during Loeng bridge. In 1970-71 was archaeologist Ole Egil Eide opportunity to dig further into the ground under the church, and found traces of burials older than the stone church, 81 in all. His interpretation is that there have been at least two churches, presumably stave churches, on the spot where the stone church was built around 1100. The oldest of the graves are dated to the radiological 980-1030, and were some of the oldest Christian burials found in Norway. Ruins of Clement's Church is now exposed and is included as part of Middelalderparken in the Old Town of Oslo.
References:The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.