A unicorn is depicted as a white horse-like or goat-like animal with a long straight horn with spiral grooves. It is also described as having cloven hooves and a goat's beard. In European art and literature, the unicorn has been depicted like this for over 1000 years. During the Middle Ages and Renaissance, it was considered an extremely wild woodland creature. It was said to be so wild that it could only be captured by a virgin. In medieval and Renaissance times, the horn of a narwhal was sometimes sold as a unicorn's horn. It was believed to have healing properties when dissolved in poisoned water, and even to make water potable.