Nessebar is generally considered safe for solo female travelers. The city is known for its friendly locals, well-preserved architectural landmarks, and beautiful beaches which are all well-patrolled. Most areas are safe to walk around, even at night. However, just like any other destination, it's advisable to maintain basic safety practices such as being aware of your surroundings, not flashing expensive possessions in public, and avoiding deserted areas, especially after dark, to avoid any potential inconveniences.