The small alleys you can play in Dingyuan at night include: 1. Dingyuan Ancient City Wall: Take a walk on the ancient city wall, enjoy the night view of the ancient city, and feel the historical and cultural atmosphere.

2. Nanguan Old Street: This is a well-preserved ancient commercial street with many quaint shops and small alleys.

3. Dingyuan County Government Office: This building was the county government office during the Ming and Qing Dynasties. It has a very unique architectural style and historical background.

4. Ancient Temple Lingyin Temple: This is an ancient Buddhist temple with a history of thousands of years. It is brightly lit at night. Here you can admire the Buddha statues and immerse yourself in the Buddhist cultural atmosphere.

5. Gaojia Courtyard: This is an ancient large-scale residential building with many unique architectural structures, decorations and cultural connotations.