Kastellet is one of the best preserved star fortresses in Northern Europe. It is constructed in the form of a pentagram with bastions at its corners. Kastellet was continuous with the ring of bastioned ramparts which used to encircle Copenhagen but of which only the ramparts of Christianshavn remain today.
King Christian IV of Denmark initiated Kastellet’s construction in 1626 with the building of an advanced post, the Sankt Annæ Skanse (St. Anne's Redoubt), on the coast north of the city. The redoubt guarded the entrance to the port, together with a blockhouse that was constructed north of Christianshavn, which had just been founded on the other side of the strait between Zealand and Amager. At that time the fortifications only reached as far north as present day Nørreport station, and then returned south east to meet the coast at Bremerholm, the Royal Shipyard. However, part of the king's plan was to expand the area of the fortified city by abandoning the old East Rampart and instead extend the rampart straight north to connect it to Sankt Annæ Skanse. This plan was not completed until the mid-1640s, shortly after King Frederick III succeeded King Christian IV.
After the Swedish siege on Copenhagen (1658–1660) the Dutch engineer Henrik Rüse was called in to help rebuild and extend the construction. The fortification was named Citadellet Frederikshavn ('The Frederikshavn Citadel'), but it is better known as Kastellet ('the citadel').
Kastellet was part of the defense of Copenhagen against England in the Battle of Copenhagen (1807). During the German invasion of Denmark on 9 April 1940, German troops landing at the nearby harbor captured The Citadel with very little resistance, thereby forcing the Danish government to surrender.
Kastellet was renovated 1989–1999 with funds from the A.P. Møller and Wife Chastine McKinney Møllers General Fund.
A number of buildings are located within the grounds of Kastellet, including a church as well as a windmill. The area houses various military activities but its mainly serves as a public park and a historic site.References:
The Mosque–Cathedral of Córdoba, also known as the Great Mosque of Córdoba and the Mezquita is regarded as one of the most accomplished monuments of Moorish architecture.
According to a traditional account, a small Visigoth church, the Catholic Basilica of Saint Vincent of Lérins, originally stood on the site. In 784 Abd al-Rahman I ordered construction of the Great Mosque, which was considerably expanded by later Muslim rulers. The mosque underwent numerous subsequent changes: Abd al-Rahman II ordered a new minaret, while in 961 Al-Hakam II enlarged the building and enriched the Mihrab. The last of such reforms was carried out by Almanzor in 987. It was connected to the Caliph"s palace by a raised walkway, mosques within the palaces being the tradition for previous Islamic rulers – as well as Christian Kings who built their palaces adjacent to churches. The Mezquita reached its current dimensions in 987 with the completion of the outer naves and courtyard.
In 1236, Córdoba was conquered by King Ferdinand III of Castile, and the centre of the mosque was converted into a Catholic cathedral. Alfonso X oversaw the construction of the Villaviciosa Chapel and the Royal Chapel within the mosque. The kings who followed added further Christian features, such as King Henry II rebuilding the chapel in the 14th century. The minaret of the mosque was also converted to the bell tower of the cathedral. It was adorned with Santiago de Compostela"s captured cathedral bells. Following a windstorm in 1589, the former minaret was further reinforced by encasing it within a new structure.
The most significant alteration was the building of a Renaissance cathedral nave in the middle of the expansive structure. The insertion was constructed by permission of Charles V, king of Castile and Aragon. Artisans and architects continued to add to the existing structure until the late 18th century.
The building"s floor plan is seen to be parallel to some of the earliest mosques built from the very beginning of Islam. It had a rectangular prayer hall with aisles arranged perpendicular to the qibla, the direction towards which Muslims pray. The prayer hall was large and flat, with timber ceilings held up by arches of horseshoe-like appearance.
In planning the mosque, the architects incorporated a number of Roman columns with choice capitals. Some of the columns were already in the Gothic structure; others were sent from various regions of Iberia as presents from the governors of provinces. Ivory, jasper, porphyry, gold, silver, copper, and brass were used in the decorations. Marvellous mosaics and azulejos were designed. Later, the immense temple embodied all the styles of Morisco architecture into one composition.
The building is most notable for its arcaded hypostyle hall, with 856 columns of jasper, onyx, marble, granite and porphyry. These were made from pieces of the Roman temple that had occupied the site previously, as well as other Roman buildings, such as the Mérida amphitheatre. The double arches were an innovation, permitting higher ceilings than would otherwise be possible with relatively low columns. The double arches consist of a lower horseshoe arch and an upper semi-circular arch.