Skyscrapers towering over cities or spectacularly-designed bridges often come to mind when we think of great feats in architecture. However, some of the most amazing structures on earth are not man-made or urban at all, but residences built by animals in the natural world.

A growing number of invasive Burmese pythons have taken up residence in the wetlands of Florida.

What happens to nature after a nuclear accident? And how does wildlife deal with the world it inherits after human inhabitants have fled?

Crow experts from around the world present us with captivating new footage of crows as we have never seen them before.

The two-part special "Dogs That Changed the World" tells the epic story of the wolf's evolution, how "man's best friend" changed human society and how we in turn have radically transformed dogs.

These tiny marvels dazzle and delight bird watchers all over the world, and NATURE reveals their stunning abilities as they have never been seen before.

Conservationist Rom Whitaker searches for the last of the supersize crocodiles among the titans of the croc world: Nile crocodiles, saltwater crocodiles, and gharials.

Just how smart are monkeys? Their curiosity leads them to try new things, but it’s their culture that teaches them much of what they know.

Can man and animal live again in what remains one of the most politically troubled and dangerous places on Earth?