The Fethiye Mosque is located on the northern side of the ancient Roman Agora in Athens and was built on the ruins of a Christian basilica from the middle Byzantine period (8th/9th centuries). The Christian church was converted into a mosque in 1456/58, soon after the Ottoman conquest of the Duchy of Athens, to coincide with the visit to the city by Sultan Mehmed the Conqueror in 1458.
Only a fragment of the mihrab survives from this mosque, which was demolished and replaced by the present structure between 1668 and 1670. The new mosque comprises a porch and a large rectangular main hall, crowned by a dome supported by four pillars. The central dome is flanked by half-domes on each side, and by smaller domes on each corner. The porch is supported by five arches, each crowned by a small dome, resting on masonry on the sides and four pillars in the middle. During the brief occupation of the city by the Venetian forces in the Morean War (October 1687 – May 1688), the mosque was converted by the Venetians into a Catholic church, dedicated to Dionysius the Areopagite.
Following the outbreak of the Greek War of Independence, in 1824 the disused mosque was used as a school by the Filomousos Eteria of Athens. At about the same time, or shortly after the end of the war, the mosque's minaret was torn down. From 1834, after Greek independence, and until the early 20th century, it was used successively as a barracks, a military prison and finally as a military bakery, at which point additions were made to the building to house the bakery's kilns. From the early 20th century it is used mostly as a storage place for various finds from the excavations in the Agora and the Acropolis of Athens.
Except for the removal of recent additions and the restoration to its original shape in 1935, the mosque has never undergone a complete restoration, and by 2010 had developed serious structural problems. In autumn 2010, the Greek Ministry of Culture ordered the emptying of the building from the various antiquities stored there, and the beginning of the process to restore it and open it to the public. Today it is open to the public.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.