Archaeologists are likening the discovery to winning the lottery. A Roman cavalry barracks has been unearthed near Hadrian’s Wall, complete with extraordinary military and personal possessions left behind by soldiers and their families almost 2,000 years ago. A treasure trove of thousands of artefacts dating from the early second century has been excavated over the past fortnight.

The find is significant not just because of its size and pristine state, but also for its contribution to the history of Hadrian’s Wall, showing the military build-up that led to its construction in AD122. The barracks pre-dates the wall: the Romans already had a huge military presence in the area, keeping the local population under control.
...
The artefacts survived because they were concealed beneath a concrete floor laid by the Romans about 30 years after the barracks was abandoned, shortly before 120. The concrete created oxygen-free conditions that helped preserve materials such as wood, leather and textiles, which would otherwise have rotted away.

Birley said: “The swords are the icing on the cake for what is a truly remarkable discovery of one of the most comprehensive and important collections from the intimate lives of people living on the edge of the Roman Empire at a time of rebellion and war. What’s exciting is that [they] are remarkably well-preserved … There is a huge range of stuff – their hair combs, pots, wooden spoons, bowls, weapons, bits of armour, and their cavalry bling.

https://www.theguardian.com/uk-news/2017/sep/09/hadrians-wall-lost-secrets-roman-vindolanda-unearthed