Let's look at how Long Island was formed around 20,000 years ago. It has to do with a glacier that brought plenty of material along with it and left some behind when it receded.

For the final days of Sigrid's visit to the New York area, she leaves the rocky North Shore and goes south to a place she knows very well from her childhood—the beach! It's a nice place to visit even in the cooler weather.

Finally home! Sigrid talks about her trip home and how it feels to be back after a month away.

Isaac travels by van through North America with his wife and his dog. Today he stops off in Quebec, Canada to tell us a little about the culture, cuisine, and most famous landmarks of this old city.

A coyote and a golden eagle fight over the carcasses of animals that did not survive the frozen winter, and a mother bobcat teaches her kittens to hunt through the snow.

Sigrid describes traveling from her home in Italy to Tacoma, Washington in the United States to care for her sister with Alzheimer's disease. She stayed there for a whole month.

Sigrid talks about the reality of conversing with someone who has Alzheimer's. They often have trouble finding the word for the thing they are thinking of.

Protected by presidential decree, the breathtaking mountainous terrain of the Yosemite Valley is now a national park, enjoyed by many human visitors, while still home to the wild creatures and stunning vegetation that has inhabited it for millennia / centuries.

Molten granite was cooled and scoured by glaciers, forming Yosemite’s almost surreal landscape with its many remarkable rock formations. Black bears inhabit the park and emerge each spring from their hibernation, ready to begin a new cycle of life.

As spring arrives, the remarkable and deadly poisonous Sierra newt moves to its traditional aquatic breeding grounds. Meanwhile, kingfishers fish the crystal clear Yosemite streams and squirrels play a dangerous game of chase with the hunting bobcats.

In the wooded valley, a pine squirrel falls prey to the voracious bobcat. Here we find some of the oldest and tallest trees on earth: The giant sequoias, which are now a major attraction for visitors to the park.

A relaxing bobcat family is surprised by the appearance of a young black bear. Elsewhere, a raven family is threatened by the presence of a bald eagle circling above their nesting site.

The imposing rock faces of Yosemite are very popular with sport climbers, and the rocky heights are also home to the endearing American pika. Mule deer, many with fawns, inhabit the lower valley, which is awash with spring color.

It’s June, and Yosemite has come alive with noise and vibrant colors. The meadow flowers are in bloom, the bobcat kittens are almost full-grown, and the park’s unique amphibian and rodent populations emerge from their winter rest.

In the lower valley, a foraging black bear attacks a colony of ants, which quickly rally to defend themselves. At its driest in summer and fall, the park is at the mercy of forest fires. One of the largest ever, the Rim Fire, broke out in the autumn of 2013, and burned out of control for over ten weeks.