This cairn comes from one of my favorite cairned trails, the ascent to the summit of Mauna Loa on the big island of Hawaii. When we hiked the trail last February, I counted over 185 cairns, ranging from just a couple of rocks to ones like this one, massive, tall, and needed. The trail is completely on basalt lava flows and without the cairns, the route up would be very challenging. The cairn also illustrates my observation that basalt, with its rough, hard surface often filled with many holes, is one of the best materials for cairn construction. That surface acts sort of like of velcro such that the rocks cling together and allow one to erect upright cairns, always something nice to see on a trail. Another highlight of this cairn was the chance encounter with the bird flying over the pile. I am not sure of the species but it was very exciting to see.