The NABC facility is nice - 2.5 acres of mostly natural Minnesota forest, with the only artificial feature being the pond and waterfalls, and the individual enclosures for each bear. This lets the bears access natural food throughout the year, dig their own dens for Wintering if they want, and in general live in a more natural environment.

It's still not the great outdoors, though, and bears do get bored. So the staff will hide food around the front of the enclosure and also stick food into objects, such as ice (great for hot days) and thick plastic objects like this cube.

https://www.bear.org/website/