Some of the things you will read about in this book may remind you of the tales of Baron M]nchausen. You will read about red-hot stones erupted by a fiery mountain being used to heat up meals, about a sea-shell that caught a black cormorant, about the golden hair of the goddess of Fire, about the magic fireworks in the crater of the Klyuchevskaya volcano (also known as the Klyuchevskaya Sopka), one of the largest in the world, about fences of whale-bone, about hot springs running down snow-clad mountains, about villages which are heated by subterranean sources, in short, about many curious things. These things are not inventions but really exist in the land of fire-breathing mountains. For many years the author has explored the Kamchatka-Kuril volcanic belt---one of Pluto's largest chains. Expeditions to study their eruptions were made in summer and winter, spring and autumn. Day after day, for years on end, the members of the expedition led a life that was strenuous but adventurous and full of vivid impressions. They heard the thunder of stone avalanches and landslides, the cannonade of volcanic explosions, heard red-hot stones whistling through the air, the roar of gas jets on the shores of hot lakes formed in craters, over which hang acrid vapours, the babbling of streams and the rumbling of waterfalls gushing down from the glaciers. They felt the fiery breath of hot lava, the trembling of volcanoes, tasted the sour snow on the craters of active volcanoes. They met many "natives" of those remote lands---shaggy bears, red and black foxes, swift-footed deers, big-horned mountain sheep, long-toothed sperm-whales and fat lazy seals. Recounting his adventures, the author tells about thestructure of the Earth, about volcanic heat, about magma, the molten rock issuing from the bowels of the Earth. He explains how volcanoes erupt and why, and provides a mass of other no less interesting facts about volcanology. Haroun Tazieff, the eminent Belgian volcanologist, once said: "I have enjoyed all the delights the profession of volcanologist has to offer, delights which are a blend of indescribable beauty and the pleasure of measuring one's strength against the forces of nature let loose, and the joy of plucking secrets from nature." There can be no better epigraph for this book.