Which emperor has been to Yuanmingyuan?

Yuanmingyuan was originally a small private garden when Yongzheng was the prince of Yong. Kangxi came to this small garden until the expansion of Qianlong in Yongzheng, and then it was burned in Eight-Nation Alliance. There should be six emperors there. They are: Kangxi, Yongzheng, Qianlong, Jiaqing, Daoguang and Xianfeng. Of course, you can count Cixi.