What is Yellowstone National Park famous for?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'QUESTIONS_ENTITY', 'name_': 'Q351', 'id': 0, 'label': 'Yellowstone National Park'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q177380', 'id': 1, 'label': 'Hot spring'}, {'type': 'INTERNAL', 'name_': 'Q1013311', 'id': 2, 'label': 'Mammoth Hot Springs'}], 'links': [{'name_': 'P3018', 'source': 2, 'target': 0, 'label': 'located in protected area'}, {'name_': 'P31', 'source': 2, 'target': 1, 'label': 'instance of'}]}