Last month a "Volcano Watch" article discussed the bicentennial of the first visit of Westerners to Kīlauea caldera, led by English missionary William Ellis, in 1823. Ellis did not just visit the summit region; he had approached from Kaʻū, traveling along what eventually became known as Kīlauea’s Southwest Rift Zone. Ellis first witnessed evidence of Kīlauea’s restlessness there, in the form of a vast, 4.8-square-mile (12.5 square-kilometer) lava flow that had erupted just a short time before.