The Roman Walls which once surrounded Córdoba, Spain, were built after the Romans captured the city in 206 BC, making it part of the Roman Republic.
Built as fortifications soon after the Romans captured Córdoba, the walls stretched some 2,650 m, completely surrounding the city. They consisted of carefully cut stone with an outer wall of up to 3 m high and a 1.2 m inner wall flanking a gap 6 m wide filled with rubble. There were several semicircular towers along the walls. When the city received the status of Colonia Patricia under Augustus, the southern wall was demolished in order to extend the city limits to the river. Vestiges remain in the Alcázar, near the Roman bridge, and flanking the Avenida de la Ribera. The walls next to Calle San Fernando and Calle Cairuán (restored in the 1950s) also have a base from this period. A section of the Roman wall can be seen from the street next to the Roman temple.
Roman gates included the Porta Principalis Sinistra (later Puerta de Gallegos) on the west side not far from the Roman mausoleum. The arches next to the Puerta de Sevilla to the east are part of a Roman aqueduct.References:
First record of Kastelholma (or Kastelholm) castle is from the year 1388 in the contract of Queen Margaret I of Denmark, where a large portion of the inheritance of Bo Jonsson Grip was given to the queen. The heyday of the castle was in the 15th and 16th centuries when it was administrated by Danish and Swedish kings and stewards of the realms. Kastelhoma was expanded and enhanced several times.
In the end of 16th century castle was owned by the previous queen Catherine Jagellon (Stenbock), an enemy of the King of Sweden Eric XIV. King Eric conquered Kastelholma in 1599 and all defending officers were taken to Turku and executed. The castle was damaged under the siege and it took 30 years to renovate it.
In 1634 Åland was joined with the County of Åbo and Björneborg and Kastelholma lost its administrative status.