Question: stone monuments often collective tombs from europe's neolithic period are often referred to as
[{'answer': 'stone circle', 'provenance': [{'wikipedia_id': '637066', 'title': 'Stone circle', 'start_paragraph_id': 1, 'start_character': 2, 'end_paragraph_id': 1, 'end_character': 14, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]