This photo was taken back in 2015 when we visiting Arizona Grand canyon National park. The view of this river valley is magnificent and visually overwhelming. Grand canyon is geologically significant because of the ancient rocks that were well preserved and exposed in the walls of the canyon. It record geologic history of the North American continent.
這張照片是2015年我們去科羅拉多大峽谷國家公園玩時照的。公園裡的風景只能用壯觀來形容。大峽谷對地理學來講有極大的貢獻，峽谷底的岩壁紀錄著北美地理環境的歷史。
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