Question: what is the plain of jars in laos
[{'answer': 'megalithic archaeological landscape', 'provenance': [{'wikipedia_id': '358780', 'title': 'Plain of Jars', 'start_paragraph_id': 1, 'start_character': 41, 'end_paragraph_id': 1, 'end_character': 76, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '358780', 'title': 'Plain of Jars', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 320, 'bleu_score': 0.879962308706789, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16074030576496241965}, 'section': 'Section::::Abstract.'}]}]