We all need to spend time alone once in a while. But Beatriz Flamini took things to a whole new level. The Madrid, Spain, resident spent 500 days alone in a cave 230 feet (70 meters) underground. Flamini was 48 years old when she went into isolation and 50 when she emerged from the cave on April 14, 2023. The extreme athlete took up the challenge to test her mental strength. She also wanted to help scientists explore the effects of isolation on the human body and mind.