English: The Valley of Ten Thousand Smokes is within Katmai National Park, Alaska, and is filled with ash flows from the 1912 eruption of Novarupta. The 1912 eruption was the largest eruption by volume in the 20th century, erupting about 13 cubic kilometers of material. The summit of Mt. Katmai stratovolacano collapsed, forming a lake-filled caldera. The 100 km2 valley is filled as deep as 210 m with ash. The Alaska Volcano Observatory continually monitors the area where there are 5 active volcanoes within 15 km. Image data for the 3-D perspective view were acquired in July 2004, and are located near 58.4 degrees north latitude, 155.5 degrees west longitude.