One of the least populated and most pristine parts of southern Oregon, the town of Cave Junction and the surrounding Illinois Valley attract outdoors enthusiasts of all kinds for hiking, backpacking, camping, fishing, and hunting. Expect rugged terrain and the chance to view some of the tallest Douglas fir trees in the state. Other than those passing through en route from Grants Pass to the northern California coast via U.S. 199, most visitors come here to visit the Oregon Caves National Monument, one of the world's few marble caves (formed by erosion from acidic rainwater). Sleepy Cave Junction makes an engaging little base camp, its main drag lined with a handful of quirky shops, short-order restaurants, and gas stations.