Pu'u Oo Volcano Trail is a 30.4 mile moderately trafficked out and back trail located near Hilo, Hawaii that offers scenic views and is rated as difficult. The trail is primarily used for hiking, walking, nature trips, birding, and horses and is accessible year-round. Horses are also able to use this trail.
Directions from Hilo: Trail head is identified by a sign on the south side of Saddle Road (Hwy 200) approximately 22.4 mi. from Hilo. Parking is limited.
Fascinating hike over a lava trail with a couple of short sections through forests. However, I would not call it easy since there are several steep slopes with loose gravel and one needs good boots and decent balance in other sections. The trail is of interest to bird watchers and those curious about volcano ecology. For a shorter hike just go in two miles or so and there is good variety. Great views of the observatories on Mauna Kea.