The cave – there's only one – contains about 3 miles of passages, explored via 90-minute walking tours that expose visitors to dripping chambers and 520 rocky steps. The trail, which requires ducking at times, follows an underground waterway called the River Styx.
Guided tours (the only way to access the cave) run at least hourly; they run half-hourly in July and August. Dress warmly, wear good shoes and be prepared to get dripped on. Due to safety, children less than 42in tall are not allowed on tours.
A handful of short nature trails surround the area, such as the 0.75-mile Cliff Nature Trail (offering good views) and the 3.3-mile Big Tree Trail (which loops through old-growth forest to a huge Douglas fir). Some fine wineries are also found in the area.
