When traveling between Xi'an and Chengdu, Reddit users frequently recommend stopping in Pingyao and Datong to experience China's rich historical heritage. Pingyao is highly praised as one of the best-preserved ancient walled cities in the country, offering a unique atmosphere with its historic alleyways, merchant mansions like the Wang Family Mansion, and impressive city walls that are especially striking at night. Datong is another popular choice, known for the magnificent Yungang Grottoes and the Hanging Monastery, both of which are considered essential sites for history enthusiasts. For those looking for shorter excursions, Tianshui is suggested as a day trip from Xi'an to explore the Maijishan Grottoes, while some travelers suggest adding a stop in Hanzhong or Guangyuan to break up the journey and explore the scenic mountain regions of Shaanxi and Sichuan. Additionally, some users suggest combining the trip with visits to nearby cultural landmarks like the Longmen Grottoes in Luoyang or even venturing further west into the natural landscapes of Jiuzhaigou if time permits.