Megastructures

Following U.S. Customs and Border Protection and U.S. Immigration and Customs Enforcement officers.

Witness the rarely seen magic of the longest river system in the United States and the drama of the creatures that are drawn to the Mississippi for survival including bears, wolves, wild boar, bull sharks and alligators. The exploration of North America's greatest waterway is a roller-coaster ride of drama with visuals sure to take your breath away.

Three years in the making, Great Migrations is a landmark series featuring the epic struggles of animal migrations around the planet, and the groundbreaking science behind these life-or-death marathons. It's a chronicle of inspiring, often harrowing journeys, unforgiving odds, and what it really means to move as though your life depends on it.

Aquatic ecologist Zeb Hogan gets up close and personal with bizarre giants of the water.

In Season 3, Hard Time takes viewers on a yearlong journey behind bars, following the lives of those who work and serve time in two of Georgia's toughest maximum-security prisons. Episodes include Battle Behind Bars, World Without Men, Women on Lockdown, Gangs vs. God, Cellphone War, Prisoner Protest, The Convict Cycle and The Outsiders.