Birtvisi is a ruined medieval fortress in Kvemo Kartli, Georgia, nested within limestone cliffs in the Algeti river gorge. It is now within the boundaries of the Tetri-Tsqaro municipality, adjacent to the Algeti National Park.
Birtvisi is essentially a natural rocky fortress of 1 km², secured by walls and towers, the most prominent of which – known as Sheupovari ('Obstinate') – tops the tallest rock in the area. Various accessory structures, an aqueduct included, have also survived.
In written sources, Birtvisi is first mentioned as a possession of the Arab amir of Tiflis of which he was divested by the Georgian nobles Liparit, Duke of Kldekari and Ivane Abazasdze in 1038. In medieval Georgia, Birtvisi entertained a reputation of an impregnable stronghold whose master could control the entire strategic Algeti gorge. The Turco-Mongol amir Timur notably reduced the fortress during one of his invasions of Georgia in 1403. After the partition of the Kingdom of Georgia later in the 15th century, Birtvisi was within the borders of the Kingdom of Kartli and in possession of the princes Baratashvili.References:
The Jelling stones are massive carved runestones from the 10th century, found at the town of Jelling in Denmark. The older of the two Jelling stones was raised by King Gorm the Old in memory of his wife Thyra. The larger of the two stones was raised by King Gorm's son, Harald Bluetooth in memory of his parents, celebrating his conquest of Denmark and Norway, and his conversion of the Danes to Christianity. The runic inscriptions on these stones are considered the most well known in Denmark.
The Jelling stones stand in the churchyard of Jelling church between two large mounds. The stones represent the transitional period between the indigenous Norse paganism and the process of Christianization in Denmark; the larger stone is often cited as Denmark's baptismal certificate (dåbsattest), containing a depiction of Christ. They are strongly identified with the creation of Denmark as a nation state and both stones feature one of the earliest records of the name 'Danmark'.
After having been exposed to all kinds of weather for a thousand years cracks are beginning to show. On the 15th of November 2008 experts from UNESCO examined the stones to determine their condition. Experts requested that the stones be moved to an indoor exhibition hall, or in some other way protected in situ, to prevent further damage from the weather.
Heritage Agency of Denmark decided to keep the stones in their current location and selected a protective casing design from 157 projects submitted through a competition. The winner of the competition was Nobel Architects. The glass casing creates a climate system that keeps the stones at a fixed temperature and humidity and protects them from weathering. The design features rectangular glass casings strengthened by two solid bronze sides mounted on a supporting steel skeleton. The glass is coated with an anti-reflective material that gives the exhibit a greenish hue. Additionally, the bronze patina gives off a rusty, greenish colour, highlighting the runestones' gray and reddish tones and emphasising their monumental character and significance.