Paricutin provides one of nature's best lessons in how volatile Earth is. Exploding out of a Mexican cornfield in 1943, Paricutin was the first known volcano to have witnesses at its birth. Within a year, the cone had grown to more than 1,100 feet high. The flow eventually spread over 10 square miles, engulfing the nearby towns of Paricutin and San Juan Parangaricutiro. The eruptions ceased in 1952, and the cone now soars 1,345 feet high.