The Oosterkerk ('eastern church') is a Dutch Reformed church built in the period 1669-1671 by architect Daniël Stalpaert and completed by Adriaan Dortsman. The church bells were cast by Pieter Hemony. The church has not been used for church services since 1962, and fell into decay since then. It was restored in the 1980s.
The layout of the church is in the shape of a Greek cross in which the space between the arms has been partially filled by lower volumes. On the canal side is the main entrance, the elevation of which is supported by a balustrade. The cornice of the lower volumes follows the relief of the walls, whereas the cornice of the Greek cross strictly conforms to the layout without acknowledging the indentations of the wall.
Some 500 people were buried in the church, including Adriaan Dortsman.
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.