Jedburgh Abbey is a magnificent ruin, definitely worth a visit. It was founded in 1147, initially as a priory, by King David I in 1138. His intention was partly to demonstrate to the English that the Scots could build on a grand scale so close to the oft disputed border between the two countries. It was captured by the English during border wars so often that it was eventually demolished in 1409, when it was the last English stronghold in Scotland.
www.undiscoveredscotland.co.uk/jedburgh/jedburghabbey/