In 955, Almería gained the title of medina ('city') by the Caliph of Cordoba, Abd ar-Rahman III: construction of the defensive citadel, located in the upper sector of the city, began in this period. The alcazaba, provided not only with walls and towers but also with squares, houses and a mosque, was to be also the seat of the local government, commanding the city and the sea nearby.
The complex was enlarged under caliph Al-Mansur and, later, under Al-Jairan, first king of the independent taifa of Almería (1012–1028).
The first line of walls is a wide enclosure corresponding to the first Muslim military camp, used as shelter for the population in case of siege. For this task it was provided with large cisterns.
The first enclosure is separated by the second one by the so-called Muro de la Vela ('Wall of the Sail'), taking its name from a bell that warned the population in case of events such as the arrival of a ship in the port, danger, fires etc. This wall was built by King Charles III of Spain.
In the second enclosure was the residence for the governors, their soldiers and their servants. It included also the mosque, baths, tanks, tents etc.
The third enclosure, the most external, is also the most modern in the complex. After the Christian conquest of Almería, the Catholic monarchs Isabella I of Castile and Ferdinand II of Aragon had a castle built in the most elevated sector of the town, more apt to resist the new gunpowder artillery.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.