AUTHOR’S NOTE: We travelled Hawaii before the WHO declared COVID-19 a pandemic and the world went on lockdown. So rest assured we’re blogging post-travels and currently self-isolating at home. Quarantine safe, everyone. — Heather & Pier
Our first morning in Hilo, we did an easy loop ride of Wailuku River State Park and Kaumana Caves.
RIDE STATS – HILO, HAWAI’I – Wailuku River State Park to Kaumana Caves
- Distance – 14 km
- Average Speed – 17 km/hr
- Top Speed – 40 km/hr
- Cycling Time – 49 mins
- Climbed – 250m
- Descended – 260m
- Steepest Grade – 8%
- Total Trip Time – 2 hrs
We did this route counter clockwise, and though the steepest grade is the same both ways, there are more sightseeing breaks and flattish spots on the uphills going counterclockwise than clockwise. Plus, we wanted to see Rainbow Falls first to catch the morning rainbow.
WATERFALLS: Wailuku River State Park
Wailuku Park stretches from Rainbow Drive just off Waianuenue Ave to Pi’ihonua Road. And our first stop in the park was Rainbow Falls!


Hawaii is very much a place where everyone drives. There are always big parking lots, but rarely bike parking. However, most sites have metal railings, and that’s where we parked the Bromptons.

There is a trail right where we parked our bikes that leads to a huge banyan tree. You can also access this place from Rainbow Drive.

From there, we returned to Waianuenue Ave, but the shoulder disappeared quickly, so we turned off onto Wailuku Drive, a quiet residential street that leads right to the next sightseeing spot – Boiling Pots.

This section of the river is called Boiling Pots because after a storm when the river rises, the water in the “lava pots” (vertical columns that formed as the lava cooled in the river bed) looks like it’s boiling. When we were there, the water was pretty low, but you get the idea!
Note: there are nicely maintained bathrooms at Rainbow Falls, Boiling Pots, and Kaumana Caves. So feel free to drink that pot of coffee before heading out on this ride because there are plenty of washrooms!

From here we headed back to Waianuenue Ave where it quickly became Pi’ihonua Rd. We stopped on the bridge overlooking the Wailuku River.

The internet tells me this is a two-tier falls, and there are photos online with this dam falls and another waterfall behind it… but we couldn’t see another waterfall. There seem to be too many trees in the way!
We retraced our route back to the turnoff to Akolea Rd. Like Waianuenue Ave, the shoulders on Akolea Rd are pretty non-existent. Luckily, there’s far less traffic on Akolea Rd and all the drivers gave us a lot of space when passing.
Akolea Rd is a steady but gentle uphill, averaging a 3% grade (highest grade 5%). The steepest part of this loop ride was from Rainbow Falls up to Boiling Pots.

This road ends at Kauma Dr where we turned left and within a couple kilometres, we saw a small parking lot on the right and the caves on the left.
CAVES: Kaumana Caves (Lava Tubes)
Like at the falls, we parked to the metal railing at the entrance.

Notice the sign that reads: “No walkway, no lights, sharp loose rocks.” These lava tubes caves are not like the tourist-friendly ones at Volcanoes National Park. They are just the caves. No one has installed lights or smoothed out a path to walk on. But my guidebook told me this, so I was prepared to use the Brompton bikes’ super bright Cateye Volt front lights as flashlights. Note that cell phone flashlights are not bright enough for the total darkness of these caves.

At the bottom of the stairs, you can go left and right. We went left first, again on the advice of my guidebook.
Kaumana Caves – Left Side
The left side caves don’t look like much at first, but once you get through the small opening, they open up into beautiful caverns with the most diverse lava formations we saw on our trip.


Lava formations.Multicoloured lava rock! Sparkly lava rock!




Kaumana Caves – Right Side
These caves are much rockier and more difficult to walk on, like the lava flowing through here was less smooth, leaving behind massive chunks of lava rock.



Through this opening, the caves were not as interesting as the other side, so I didn’t really take pictures, and we soon turned back. If you are claustrophobic and don’t want to venture far into these dark lava tubes, the right side caves offer a lot to be seen in the wide open space near the opening.


After the caves, the bike ride back into Hilo involved a fun “screaming descent” where we got to a top speed of 40km/hr!
Overall, this is a pleasant ride with pretty scenery and smooth paved roads and lots of beautiful sights to see, especially the amazing lava tubes of Kaumana Caves.
Next up… we cycle Hilo’s beach strip!