The wall around Lucca is about 4 km. It's the perfect length to walk, run or bike around. On our visit my husband and I were able to use bicycles from the Hotel that we stayed at and rode the 4 km around the fortress. If you walk or bike around the city it will give you a good idea of the layout and you can then go back to the areas that interested you. There are lots of interesting sites within the city walls. Museums, basilicas, churches and a variety of interesting shops and eateries. Catch views of beautiful garden balconies, church bell towers and see amazing architecture.