Ko Lanta in Thailand is generally considered quite safe, even at night. While isolated incidents can occur, it is not common. It's recommended to stay in well-lit and populated areas, use reputable transport services when traveling at night, and always be mindful of your surroundings. Local people are hospitable and the crime rate is relatively low. However, caution should be used, as in any other location, particularly when walking alone at night. Avoid unlit and deserted areas.