Olympic National Park is a truly unique site, known widely for its diversity; here you can experience one of the largest temperate rainforests in the US, witness huge snowy mountains, view scenic rivers, and walk along 70+ miles of coastline without ever leaving the park. The park includes four major ecosystems: subalpine, temperate rain forest, coastal, and lowland forest. If you're looking for vast wilderness, Olympic National Park is the place to go. There is something for everyone here: fishing, hiking, biking, boat tours, paddle boarding, and even spots to dine and shop throughout the park. Lake Crescent, a glacially carved lake, is a great place to visit for some of these activities - here you can rent a rowboat or kayak, or go for a picnic. With its clear waters and beautiful scenery it is definitely a spot you can stay at all day.
Source: U.S. Department of the Interior, National Park Service