Soledar Salt Mine
During the Battle of Soledar on 5 January 2023, the Wagner Group and Russian Armed Forces took parts of Soledar’s east, forcing the Armed Forces of Ukraine to step back and take up defences further west and in the central parts of Soledar.[12] The salt mine has since become a critical point for the Ukrainian defence of Soledar and Bakhmut, utilizing the deep tunnels of the salt mine to maintain a defensive line in Soledar, as well as to keep stockpiles of supplies and launch attacks on Russian positions from their rear.[13] On 10 January 2023, pro-Russian outlets, including Wagner Group leader Yevgeny Prigozhin, claimed the mines were largely occupied by Russian and Wagner Forces, although these reports were not independently verified.[14] However, between 11 and 13 January 2023, major Russian offensives towards the central part of Soledar made large progress. At the same time, Russian forces north and south of Soledar made large advances over the countryside to the roads, threatening encirclement of the central parts of Soledar. Thus, the Ukrainians were forced to step back to the west of Soledar, putting much of the Soledar Salt Mine under Russian control.[15][16]
https://en.wikipedia.org/wiki/Soledar_Salt_Mine
‘...with guided tours costing visitors a few hundred dollars.”
No thanks, I’ll keep my few hundred, I can’t imagine a salt mine that interesting.