Our planet Earth is filled with breathtaking wonders. From the vast oceans and mighty mountains to the babbling brooks and smallest grains of sand, from the largest whales and swiftest birds to the tiniest microbes and slowest slugs, the countless living and nonliving things never cease to amaze us. In this special collection on The World of Nature, we invite you to take a tour of many of these marvels and discover some of their secrets.

        The articles in this collection are grouped according to topical categories, as seen in the box on the right. If you click on any topic, you will see the corresponding set of stories listed in chronological order, with the latest one placed first.

        Some topics, such as Birds or Mammals, contain articles about biological species or groups of species. Other topics deal with more general themes. For instance, if you wish to learn about ecosystems and keystone species that support them, go to Ecological Specialties. If you are interested in geological features--past and present--click on Geological Formations, Flows, and History. For seasonal topics such as migration or hibernation, look under Seasonal Features.

        If you wish to explore phenomena in the sky--such as cloud formation, auroras, or green flashes--click on Skyscapes. For articles on drastic natural occurrences such as thunderstorms, earthquakes, and volcanoes, look under Nature's Fury. Stories on noteworthy and unusual subjects, such as camouflage in nature, toxic birds, and carnivorous plants, are listed under Special Topics. Some stories, of course, fit more than one category.

        We hope you enjoy your tour--and, as always, we welcome your comments.