There's a castle made of salt - Apparently.
The Hallstatt Salt Mines in Austria feature a 16th-century castle carved directly into the salt walls of the mine. This unique structure, known as the "Salt Mine Chapel", was built by miners as a place of worship and features intricate stone carvings and a chapel. The castle's existence is a testament to the importance of salt mining in the region's history, and it remains a popular tourist attraction today. Visitors can even take a guided tour of the mine and see the castle up close.