One of your first stops should be Xiangshan Visitor Center. Here, you'll be able to find your bearings and get lots of useful information before you set out exploring.
You'll find this tourist information center in Yuchi. If you're traveling on a budget, you'll be pleased to know there is no charge to visit. When you're done exploring Xiangshan Visitor Center, look up some attractions nearby. Formosan Aboriginal Culture Village, Yidashao Pier and Shueishe Pier are a few recommendations.
