It's more cost-effective to take a train from Shenyang to Dandong. The fastest one is less than four hours at around 8 o'clock, and there is another one at around 1 o'clock in the afternoon. On the first day, you can go directly to Phoenix Mountain for a day, stay in Dandong in the evening, and take a stroll by the river. On the second day, you can go to Wulongbei to soak in a hot spring. When you stay in Dandong, you can stay in Dantie Building next to the railway station. It's cheaper than 1 yuan a day, and you eat a lot of Dandong snacks, making cakes and barbecues.