The Achi monastery is a single-nave hall church, built of hewn stone. Constructed at the end of the 13th century or in the early 14th, it was later reroofed, renovated and surrounded by a defensive wall. The whole interior is frescoed. Some murals, stylistically dated to the late 13th century and betraying affinities with the Palaeologan art, are iconographic rarities, such as those depicting the life of Saint George.
The Achi monastery was favored by the Princes of Guria, especially Simon I Gurieli and Kaikhosro I Gurieli in the 17th century. Both made significant donations to the church and Kaikhosro made it a metochion of the bishopric see of Shemokmedi. The abbotship of Achi was then hereditary in the Salukvadze-Taqaishvili family. The church housed a gilded silver cross with a Georgian inscription mentioning the queen Tamar, which was discovered by Ekvtime Taqaishvili. The item was preserved in the Salukvadze family during the Soviet period and returned to the Achi church in 2015.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.