Look inside the richest and oldest Library in the world

Picture taken on April 20, 2018 shows the Abbey Library in north-eastern Switzerland's St. Gallen city. The library is one of the richest and oldest in the world and contains 170,000 works and some 2,100 original medieval handwritten manuscripts, including the earliest-known architectural plan drawn on parchment. (Xinhua/Xu Jinquan)