Vidin is generally considered safe for solo female travelers. The locals are normally friendly and helpful. However, it's always essential to remain cautious especially during the night and when visiting less crowded areas. The most common issues recorded are small-scale scams and pickpocketing, but violent crime is quite rare. Bulgarian law enforcement authorities are generally responsive and professional. In short, be alert, know your surroundings and take the usual precautions, and you should enjoy a hassle-free visit to Vidin.