You can go to Xizhimen and live there. A better one is Shangri-La. It's a five-star hotel, and a nearer one is Xiyuan Hotel. After staying in the hotel, you can find the concierge department and let them rent a taxi for you. If you go to the Great Wall, it's 200. It should be like this. There's no taxi on the other side of the Great Wall, so it's better to take a taxi. In this case, you can take a taxi to the subway entrance, take Line 2 from Xizhimen to Tiananmen and the Forbidden City!