Not only is there spectacular scenery and tons of hiking around Zion National Park, there are also some indoor activities to enjoy. There are two Visitor Centers, the Kolob Canyons Visitor Center at the West Entrance (exit 40 along I-15) and the Zion Visitor Center at the south entrance.
The inside of the Zion Visitor Center has only a few displays indoors along with a bookstore. The majority of the center and interpretive signs are outdoors. This allows for large volumes of people to read the interpretive signs and use the restrooms in a large area. There are lots of seating areas that are shaded that must really help in the summer when the park is at capacity. There are a few short hikes around the Visitors Center which run along the North Fork of the Virgin River. This is also the place to catch the shuttle buses. During the peak seasons (spring to fall), The Zion Scenic Canyon Drive is open to shuttle buses only with regular shuttle stops all along the road where you can hop on/hop off.
Further north on the road about 5 minutes is the Zion Human History Museum which has a spectacular backdrop of scenery (Towers of the Virgin and Bridge Mountain) along with a nice gift shop with fabulous paintings and a few human history exhibits. There is also a short (about 22 minute) movie every 30 minutes about Zion that is interesting. While we were there the Plein Air Art Invitational was going on so an artist was in the back porch area of the Museum doing a painting demonstration.
Further north on the Zion Scenic Canyon Drive is the historic Zion Lodge with a gift shop, restaurants, restrooms, and of course, lodging. The upstairs restaurant has a deck which is wonderful to sit out on and enjoy your drink and people watch.