The John Rylands Library will be moving some of its collections nearly 500 feet underground to a former salt mine called DeepStore. https://rylandscollections.com/2025/02/24/deepstore-an-answer-to-a-gritty-problem/
(Coworker on my fourth day on the job there: “Dammit, if you say ‘Well, back to the salt mines’ one more time…”)