We were in Shiga Kogen last month and headed to Joshinetsu-Kogen National Park to see the snow monkeys. These monkeys come down into the valley daily to relax in a hot spring and have their picture taken. The monkeys are blissed out and so used to people that you can get right next to them and they completely ignore you.
The hot springs is a bit of a walk from the parking area. It takes most people 30-45 minutes but our enthusiastic 3 year olds made it in about 1 hour and 15 minutes. On the way back they wanted to be carried so we made it much faster. We went really early in the day – the trail is heavily used and can get muddy or slippery as the day goes on. Fortunately the walk is through an absolutely beautiful snow-covered forest and enjoyable at any speed.
It was a huge hit with the kids.