It is believed that the hilltop Hartenstein castle was built by a possible descendant of the Kuenringer family, Heinricus de Hertinsteine, mentioned in records from 1187.
In the second half of the 17th century, the castle lords preferred more comfortable residences, abandoning Hartenstein to decay. Despite this, the castle withstood a brief siege by Swedish forces in 1645, who nevertheless destroyed an outer fortification. In 1726, Emperor Charles VI granted the estate to Baron Philipp Ferdinand von Gudenus, whose family retained it until 1927. From 1780 to 1799, Johann Heinrich von Gudenus used salvageable materials from the castle, such as doors and window frames, to build his hunting lodge, Els. By the early 19th century, the two towers were used as granaries. In 1892, Dr. Otto Pospischil leased the estate and converted the outer castle, rebuilt in a 'castle style' between 1892 and 1896, into a hydrotherapy facility. Meanwhile, the main castle had long fallen into ruin. During the Nazi era, the site served as a youth castle.
Below Hartenstein Castle lies the Gudenus Cave, eroded from the riverbank and inhabited by Neanderthals during the Stone Age. It holds the earliest settlement traces in Lower Austria, nearly 100,000 years old, including hand axes and other tools.
Dryburgh Abbey on the banks of the River Tweed in the Scottish Borders was founded in 1150 in an agreement between Hugh de Morville, Constable of Scotland, and the Premonstratensian canons regular from Alnwick Abbey in Northumberland. The arrival of the canons along with their first abbot, Roger, took place in 1152.
It was burned by English troops in 1322, after which it was restored only to be again burned by Richard II in 1385, but it flourished in the fifteenth century. It was finally destroyed in 1544, briefly surviving until the Scottish Reformation, when it was given to the Earl of Mar by James VI of Scotland. It is now a designated scheduled monument and the surrounding landscape is included in the Inventory of Gardens and Designed Landscapes in Scotland.
David Erskine, 11th Earl of Buchan bought the land in 1786. Sir Walter Scott and Douglas Haig are buried in its grounds.