The Ancient Agora of Classical Athens is the best-known example of an ancient Greek agora (central public space in ancient Greek city-states), located to the northwest of the Acropolis and bounded on the south by the hill of the Areopagus and on the west by the hill known as the Agoraios Kolonos, also called Market Hill. The Agora's initial use was for a commercial, assembly, or residential gathering place.
Agora contains several remains of ancient temples and buildings. Temple of Hephaestus is one of the best-preserved Greek temples, built around 450 BCE. The excavations has uncovered most of the over 30 known major buildings from the Agora, along with thousands of artifacts. Conservation efforts have restored thousands of pieces of pottery and amphora (the standard storage vessel of the ancient world), studied thousands of marble statues and reliefs, and analyzed the remains of human and animal bones to give us a better understanding of what life was like in the ancient Athenian world.
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.