Center City and the major tourist destinations are generally safe and well lit, but it's always smart to take certain precautions. You should always be aware of your surroundings—take care not to count change on the street or regularly flash an extremely expensive camera, phone, or tablet. Keep your purses and bags on your lap—not on the floor or dangling on the back of your chair—in restaurants and theaters. (Many thoughtful eateries install hooks on bars and tables for this purpose.) Ask hotel personnel or guides about the specific feel of places you're interested in visiting. As you would in any city, keep your car locked and mind your possessions carefully. Remember to remove valuable items from your car.
During the day, subway cars are crowded and safe, but some platforms and cars can be relatively empty during late-night hours. Although crime is relatively low in areas like Rittenhouse Square, other hot spots can be a bit trickier. South Street and Old City attract a young crowd that can get rowdy, though the areas are well patrolled by police, both on foot and by bicycle.