The cryptoporticus (covered corridor or passageway) of Arles, dating from the 1st century BC was built as foundation for the forum, which has since been replaced by the Chapel of the Jesuit College and the City Hall. Three double, parallel tunnels arranged in the form of a U are supported by fifty piers. Masons' marks on the stonework indicate that it was built by Greeks, probably from Marseille. Similar structures in Narbonne, Reims, and Bavay were used as granaries. The cryptoporticus at Arles is, however, too damp for prolonged storage and may have served as a barracks for public slaves. The cryptoporticus of Arles is listed as a UNESCO World Heritage Site, together with other Roman buildings of the city, as part of the Arles, Roman and Romanesque Monuments group.
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.