Fuyuan takes an area of serene natural beauty and tames it just enough to make accessible the abundant birdlife and multitudinous butterflies that flit between lush woodlands, mossy rocks and an attractive riverside. There's also a more manicured garden and butterfly houses for both living and pinned specimens. Several forest trails link up into a 3.5km loop, with shortcut options. The outdoor hot-spring area (extra fee) is far more tempting than Ruisui's public version.
Near the car park is a small area of rare surviving camphor trees, festooned with epiphytes. In the late 19th and early 20th century, Taiwan dominated the world market of camphor production that was used in everything from embalming fluid to medicine to insect repellent.
Inside the park, Butterfly Valley Resort is an upper market hotel whose excellent rooms come with walk-in hot-spring bathtubs (from NT$6300 half board). Non-guests can dine at the restaurant (mains NT$260–320). The reserve is 3.5km west of Fuyuan train station. From the Ruisui hot-spring area, a scenic and delightfully quiet route uses Rte 花55.