One of Korea's smallest parks, Gyeryongsan means ‘Rooster Dragon Mountain’ because locals thought the mountain resembled a dragon with a rooster’s head. At the eastern entrance is the temple Donghak-sa; at the western entrance, Gap-sa. A trail between the two temples runs along streams and small waterfalls (and a few peaks if you wish). The total hike takes between four and six hours, depending on the route. There is excellent English-language signage throughout.
With its easy access from Daejeon, most people start at the eastern entrance, from where it's a 15-minute walk to Donghak-sa, one of Korea's few nunneries. Just before the temple, look for the trail that leads you on an easy one-hour trek up to the Brother & Sister Pagodas (Nammaetap; 남매탑) – twin Silla-era pagodas that are said to represent the brother and sister who founded the original hermitage here.
Continue up to Sambul-bong Gogae (Sambul-bong Ridge), where the trail splits. From here you can continue on to the peaks Sambul-bong (775m), Gwaneum-bong (816m) and Yeoncheong-bong (738m), before wending down to Gap-sa (5.5km, four hours), or head directly to Gap-sa (2.8km, 1½ hours). The latter route passes the small waterfall Yongmun Pokpo and the hermitage Sinheung-am.
Depending on your route and schedule, you might come across other hermitages, like Daeja-am, Deungun-am or Mita-am, or a small waterfall, Eunseon Pokpo, which is between Donghak-sa and Deungun-am.
Gap-sa's main hall contains three gleaming Buddha statues, while a smaller shrine houses three shamanist deities – Chilseong, Sansin and Dokseong. From Gap-sa, it's another 15 minutes to the bus stop. The hike is slightly more difficult going in the other direction.
