There are many hot springs near Kurobe Gorge, especially in the Unazuki Onsen area. After exploring the gorge, you can relax in a hot spring. It really makes for a perfect trip.
This place gets really crowded during the fall foliage season. If you have the energy, I recommend hiking up to the top of Futago Mountain—the views up there are even more stunning.
You can still see the wooden buildings from the Taisho era here. At night, the snowy scenery and the lights create an absolutely beautiful view. It's also known as the hometown of Oshin.