Listening Hall: Located in the Summer Palace, facing Kunming Lake and backed by Wanshou Mountain, it was originally the place where Qianlong and Cixi hosted banquets. Now, as a banquet place, it has received heads of state from hundreds of countries and is a famous imperial restaurant in China.
In addition, there are snacks in Suzhou Street behind Wanshou Mountain.
Others include sausages, corn, instant noodles, etc.
The food in the park is super expensive. I suggest buying some bread, tomatoes, cucumbers, sausages and water before going. Take it with you. One person is enough.