Oregon Caves National Monument, 19000 Caves Hwy, Cave Junction, OR 97523, ☎ +1 541-592-2100 ext. 262 (fax: +1 541-592-3981), . Daily between spring to Thanksgiving, hours and tour frequencies vary, see website for details. Declared a National Monument by President William Howard Taft, the centerpiece of this attraction are the marble caves with unique rock formations. National Park Service rangers conduct guided tours on regular schedules. Bring a jacket as the temperature in the caves is a constant 43 degrees Fahrenheit (6 degrees Celsius) year-round.$8.50 adults, $6.00 children (to 16), group rates available (12 or more).