Olympic National Park is almost like three national parks in one - there's the glacier capped mountainous section (Hurricane Ridge), the Rainforests (Hoh and Quinault rainforests) and the rugged coasts (Ruby and Rialto beaches among others).
Hurricane Ridge
Far prettier in winter than in summer, this is a good drive up from the foot of the park boundary near Port Angeles. From higher elevations, it is possible to see all the way to Canada from here.
Hoh Rainforest
Some portions of Olympic National Park get so much rain that it looks less like the glacier tipped sections of Hurricane Ridge and more like a tropical rainforest complete with high humidity and moss hanging off humungous trees. There are two such very lush sections - Hoh and Quinault Rain forests. Accompanying all this moisture are waterfalls, Sol Duc Falls is the biggest and best known of all the falls. Madison Falls is a short hike away.
The Ocean and Beaches
The third section of Olympic National Park is the western coast. This section of the park is a narrow strip along the coast, full of rugged beaches winding its way in and out of Native American Reservations like the one at La Push. This is the place to look for Seastacks - iconic representations of the entire park.
Along the Way
Crescent Lake, between the Hurricane Ridge entrance and the Hoh Rainforest entrance into the park is a beautiful, calm place and an excellent location for sunset viewing. Try and stay at the lodge if slots are available.