Day 8: Katherine to Jabiru
Today, we're heading into the heart of the Top End, as the locals call it, right into Kakadu National Park. Our destination is Jabiru, a mining town on the edge of Arnhem Land, a largely trackless 37,000-square-mile wilderness of thick scrub and crocodile-infested rivers.

This is "Crocodile Dundee" country-literally. We turn off the Kakadu Highway just past the Mary River Roadhouse and onto the dusty, badly corrugated road to Gunlom Falls. Several scenes from the movie were filmed right next to the main waterhole. We hike up to the top of the falls (now dry) in the steaming heat to find a couple of big pools of cool, clear water stepping down to the rock lip where the creek cascades to the main waterhole below. It doesn't take much to persuade several of our party to dive in.

There are signs at every river and creek crossing warning of saltwater crocodiles. The warnings are no joke; one or two people are killed by crocs up here every year. The irony is the saltwater crocodile was nearly hunted to extinction in the early part of the 20th century. My dad, who drove to Darwin with a buddy in 1953 to shoot saltwater crocs, often says: "Fortunately, we never found one." And he's only half joking: Now a protected species, big males often reach 20 feet or more in length.

We get up close and personal with our first crocs at Yellow Water, where a sunset cruise on the wetlands of the South Alligator River -- mistakenly named by an explorer who thought the crocs were gators -- reveals an astonishing array of wildlife. Mostly the crocodiles are catching the last rays of the sun on a mudbank, but every so often one slides silently into the water and glides noiselessly alongside our boat, mere feet away. The crocodile hasn't changed all that much since dinosaurs roamed the planet, and it's a chilling experience to come eye to eye with one of these primordial killing machines.