The Monastery of Serra do Pilar has been a Cultural Heritage of Humanity site since 1996 and provides an unequalled view of the city of Porto. Its construction began in 1538 and it was completed in 1670. It housed the Augustinian Friars of the Monastery of Grijo until it became occupied by the Liberal army during the Civil War of 1832-1834, during which it was damaged. The Royal Brotherhood of Nossa Senhora do Pilar, established in 1834 and, later, the Group of Friends of the Monastery of Serra do Pilar, created in 1925, helped save the monastery.
The church with its circular floor plan is unique in Portugal, as is the Cloister, which is also circular and is lined with 36 Ionic columns. It currently houses North Heritage. In the cloister, note the statue of D. Afonso Henriques, by Soares dos Reis, which is the plaster version of the one in bronze at the Guimarães Castle. It is worth taking the guided tour which includes a climb to the dome. It's a 100 steps to the circular terrace that surrounds the dome of the church, but the panoramic view over Porto is spectacular.
Serro de Pilar is part of the UNESCO World Heritage site Historic Centre of Oporto, Luiz I Bridge and Monastery of Serra do Pilar.
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.