THREE grottoes at Dunhuang in northwest China have been replicated in the city’s tallest building for an exhibition which opens next month. The full-size facsimiles — two grottoes from Mogao Caves and one from Yulin Caves — have been installed in the 632-meter Shanghai Tower. Dating from the 5th to early 11th centuries, they show the typical features of three different periods of the Dunhuang grottoes, the world’s largest treasury of Buddhist art, said Mi Qiu, curator of the exhibition.