South of Hilo is the district of Puna. There are great natural areas in Puna, including a warm pool for swimming and steam vents for a natural sauna. A couple state parks, a black-sand beach, and a quaint town round out the Puna experience.
To visit these places, there is a convenient triangle-shaped drive. From Hilo, take Highway 11 southwest, then turn left on Highway 130. First you will come to the town of Pahoa, which my traveling companions said was a nice town worth stopping in. Continue south on Highway 130 another 3.5 miles from Pahoa to find the steam vents. These are not marked, but there is a wide paved pullout on the left side along the highway near mile marker 15. Various short trails wind around the area to different steam vents. The best one I saw was a cave with a small opening (an average-size adult can go through) that made a perfect natural sauna.
Highway 130 eventually connects to Highway 137 at the site of the former town of Kalapana. Despite all efforts to re-route a lava flow in the late 1980s, 100 homes were buried in 1990. Turn left on Highway 137 which follows the coast. The drive is filled with ocean views and beautiful tunnels of vegetation. Kahena Beach is the first beach you will come to. It is a black-sand beach that is "clothing optional."
Next, we stopped briefly at McKenzie State Recreation Area. This park is a real beauty, with a forest of Ironwood trees making a blanket of soft needles. There was a picnic pavilion, but the bathroom was horrible. I loved the 40-foot sea cliffs, with pounding waves and dramatic views. Here you will find a piece of the King’s Trail, an ancient route used to connect fishing villages and sacred spots.
Continue east on Highway 137 until you see a sign for Isaac Hale Beach Park where you will turn right. Continue one mile past Isaac Hale Park to get to Ahalanui Beach Park. This is the location of a warm pool. The pool is a combination of water from a hot spring, and fresh ocean water cycling in from an inlet, which results in a perfect 90 degrees F, and a perfect combination of fresh and salt water. The day we went, there was unfortunately a large group of schoolchildren on a field trip, so it was a bit crowded. But I think normally weekdays would be good, and early morning might be especially peaceful.
To finish the day, return back to HIghway 137 and turn right. Next, turn left on Highway 132 near Kapoho. This scenic drive will go past Lava Tree State Park, site of some lava tree molds created in 1790 when the former ohi’a rainforest was covered in lava. Trees burned away, but lava had cooled around them forming molds. There is a 20-minute-loop walk. Finaly, it is 2.5 miles back to Highway 130 and the end of Puna loop.