At one point the river heads underground through lava tubes and pops up in the most vivid aquamarine pond. We clambered down a cliff and dove into the coldest water I have EVER swam in.
Further down the trail, we had a serious mishap when Andrew fell over his handlebars as his bike slid off a 40 foot cliff into the river! We were able to climb down and retrieve the bike, which seems to have survived fairly unscathed. Andrew was able to ride 15 miles on it to the end of the trail!
The ride was pretty long, with some rough lava sections, but all it all, it was super beautiful and well worth the trip.