"Yellowstone, the Grand Canyon, Mount Fuji, the Galapagos Islands. These natural wonders are on everyone's list of must-see attractions that are both spectacular and geologically fascinating. But what of Ha Long Bay, the Columbia Glacier, Erta Ale lava lake, and the Great Blue Hole? They also belong on the list, along with more than 200 other sites, both famous and obscure, that are well worth a visit to see breathtaking vistas combined with the grandeur of geological forces in action. Shaped by erosion, plate tectonics, volcanic eruptions, and other processes over the course of billions of years, Earth is a planet of immense variety. Impressive geological scenes are everywhere. But only a select few-whether astonishing valleys, mountains, waterfalls, or other formations-qualify as geological wonders that are not only memorable and worth a special trip, but that also tell us something profound about the way the world works. For example, consider these lesser-known but awe-inspiring places: Ha Long Bay: Thousands of limestone towers soar upward out of this bay of mystery and beauty in Vietnam. The formation is what geologists call a karst landscape, sculpted from the slow dissolution of soluble rock by rain and groundwater. Columbia Glacier: One of the most intensively studied glaciers in the world, this magnificent river of ice twists its way for 50 kilometers from Alaska's coastal range into the sea. Such glaciers advance and retreat for unknown reasons. Erta Ale: In rare cases, lava from a volcano will continuously feed into the volcanic crater and bubble away like a seething caldron. Of the five active lava lakes in the world, the longest running is in a volcano called Erta Ale in Ethiopia. Great Blue Hole: What could cause a nearly perfect circle of intensely deep blue water in the middle of a shallow reef? The Caribbean's Great Blue Hole tells a surprising story of repeated glaciations and rising and falling seas. Whether you are planning your next vacation or exploring the world from home, you owe it to your planet to know the places that make it exceptional throughout the solar system. The World's Greatest Geological Wonders: 36 Spectacular Sites is your gateway to an unrivaled adventure. In 36 lavishly illustrated half-hour lectures that are suitable for nonscientists and geology enthusiasts alike, Professor Michael E. Wysession of Washington University in St. Louis introduces you to Earth's most outstanding geological destinations. During more than three decades as an award-winning teacher and geophysicist, Professor Wysession has traveled the globe, getting to know Earth's most intriguing geological formations. In The World's Greatest Geological Wonders, he focuses on the leading contenders in 36 categories, from deserts to river deltas to fossil quarries to fjords. After touring his top choice in detail, he presents at least four runners-up that are every bit as spectacular. By the time you complete this course, you will have experienced more than 200 different geological wonders in nearly 120 countries. Prepare to Be Surprised Geological wonders impress us for many reasons. They are exceptionally beautiful or mysterious. They relate to us on a practical level, cutting a natural route through a mountain range or providing a source of valuable minerals. They may have played a role in human history, such as the picturesque Greek island of Santorini, which is the remnant of a volcano that erupted in ancient times, possibly ending the Minoan civilization. Natural wonders also teach us about Earth's interconnected systems, and they put time into perspective. A million years is nothing in the life story of a canyon, a cave, or a continental rift. Moreover, great landscapes, like great works of art, surprise us: Grand Canyon: No one is prepared for that first glimpse of the Grand Canyon, which suddenly appears as a breathtaking series of chasms in a seemingly featureless plateau. Which raises the question: Why is there a deep canyon here at all? Himalayas: If you go to the top of Mount Everest, you will find marine limestone with fossils. In other words, the roof of the world is made of rocks that came from the bottom of sea! Nothing better demonstrates the power of Earth to move crustal plates. Amazon basin: The Amazon is a river of superlatives. At the point where it drains into the Atlantic Ocean it contains as much water as the next seven largest rivers combined. Twenty percent of the fresh water entering the ocean comes from this mighty river basin. Hawaii: The big island of Hawaii is not only the biggest volcano on Earth; it's the biggest mountain on Earth of any kind. Measured from its base on the sea floor, it is almost twice as high as the tallest land mountain. Fire up Your Imagination! As part of your grand tour, Professor Wysession often gives tips on side trips and other attractions you can find when you visit one of the sites on his list. He also gives cultural background. For example, many geological wonders, such as Mount Fuji in Japan and Ayres Rock in Australia, have long been considered sacred to the people who live in their vicinity. Other locations may seem at first glance to be overwhelmed by hotels, shops, and other tourist amenities. But most of these sites are so vast that it's not hard to escape into pure nature. And in all cases, if you know the story behind the place that you're visiting, then just being there, even for a short time, is an experience never to be forgotten. The World's Greatest Geological Wonders takes you to stunning locales that spark your imagination. One of the top wonders in anyone's book is Yellowstone National Park, located primarily in Wyoming. The geysers, bubbling hot springs, and colorful geological formations are awe-inspiring to behold. Even more awesome is the knowledge that nearly the whole park is an enormous volcanic crater, sitting atop a massive, active magma chamber that could erupt at any time. A look at a map of North America shows that the continent has been slowly drifting across a hotspot in Earth's mantle, which has been responsible for a whole series of "Yellowstones" over the course of millions of years. The course also probes questions such as these: Why do waterfalls form? Standing at the dazzling Iguazu Falls along the border of Brazil and Argentina, you may wonder why such features are so rare, since rivers and cliffs are common. Learn that the distinctive structure of the rock beneath a river determines whether falls will form. Why does nature prefer hexagons? On close inspection, Devils Tower in Wyoming is made up of hexagonal columns of volcanic rock. Probe the connection between this geological feature and the cells of a honeycomb or the tiles on a bathroom floor. Are meteor craters always circular? Meteor Crater in Arizona is nearly circular, as are most of the countless craters on the moon-even those formed by meteors that strike at low angles. Investigate the amazing physics of an object impacting at escape-velocity speed. Where are the still undiscovered natural wonders? All of the spectacular geological formations on the surface of Earth have been found. But underground, dramatic caves wait to be discovered. Explore an exceptional example that recently came to light in Mexico. Professor Wysession winds up the course with a tour of geological wonders on other planets, as Earth is not alone in having impressive volcanoes, canyons, and other attractions. But Earth's combination of plate tectonics, flowing water, a relatively dense atmosphere, and life has created formations that are unique in the solar system. Take advantage of The World's Greatest Geological Wonders to discover what makes our planet so spectacular. There's truly no place like home!"