Piedras Negras can present certain challenges for solo female travelers. While it boasts attractions like the Plaza de las Culturas, it's primarily a border town with a substantial level of crime, including both petty and violent instances. It is advisable to remain vigilance, avoid night-time travel and stick to tourist-populated areas as much as possible. Local authorities recommend travelers to refrain from display of wealth in order to avoid drawing attention. Also, always ensure that your travel documents are in order and copies are kept separately from the originals for safety.