The Tsarichina Hole is the site of a bizarre and controversial archaeological dig that began in 1990 near the village of Tsarichina. Officially, the Bulgarian military searched for hidden treasure, but rumors soon spread that strange phenomena plagued the excavation: glowing lights, unexplained illnesses, psychic visions and the sensation of a powerful presence underground. Some researchers and witnesses claim the site is connected to a mysterious non-human entity or ancient alien being. The dig was abruptly sealed in 1992, and the hole remains a source of enduring speculation, making it one of Eastern Europe’s strangest unsolved mysteries.