To the west of the Dionysos theatre and quite close to the cliff of the Acropolis lies the Asklepieion, the sanctuary of the healing god Asklepios dated to 420 BC. Functioning pretty much as hospitals, the asklepieia were of immense importance in ancient Greece, the most popular being the Asklepieion of Epidaurus. Besides the usual facilities for sheltering the pilgrims, the core structures of the Athenian complex were the temple of the god and the enkoimeterion (dormitory). That was a large two-storey stoa for the enkoimesis of the patients, a dream-like and rather hallucinatory state of sleep induction, practised in those shrines. While in hypnotic state, the patients waited to receive a dream vision of the god who would either give medical advice or even miraculously cure them. Votive offerings that came to light from the site often depict healed body parts. Characteristic examples are on display in the Acropolis Museum.References:
Ängsö Castle was first named as "Engsev" in a royal charter by king Canute I of Sweden (r. 1167-1196), in which he stated that he had inherited the property after his father Eric IX of Sweden. Until 1272, it was owned by the Riseberga Abbey, and then taken over by Gregers Birgersson.
From 1475 until 1710, it was owned by the Sparre family. The current castle was built as a fortress by riksråd Bengt Fadersson Sparre in the 1480s. In 1522, Ängsö Castle was taken after a siege by king Gustav Vasa, since its owner, Fadersson's son Knut Bengtsson, sided with Christian II of Denmark. However, in 1538 it was given by the king to Bengtsson's daughter Hillevi Knutsdotter, who was married to Arvid Trolle.
In 1710, the castle was taken over by Carl Piper and Christina Piper. Ängsö Castle was owned by the Piper family from 1710 until 1971, and is now owned by the Westmanna foundation. The castle building itself was made into a museum in 1959 and was made a listed building in 1965. It is currently opened to visitors during the summers.
The castle is a cubical building in four stores made by stone and bricks. The lower parts is preserved from the middle ages. It was redecorated and expanded in the 1630s. The 4th storey as well as the roof is from the expansion of Carl Hårleman from 1740-41. It gained its current appearance in the 1740s.