US national park (8)
I believe the answer is:
yosemite
'us national park' is the definition.
(national park in California)
This is all the clue.
(Other definitions for yosemite that I've seen before include "US National Park in California" , "Area of beauty" , "Where there are watery cascades" , "Californian national park" , "California falls, valley, park" .)