First we passed through a p'ai-lou (memorial arch), richly ornamented with bright green and rec-faience, with three archways, and three small, gracefully shaped roofs. In former times it was forbidden for the profanum vulgus to go farther than this p'ai-lou; only the monks and the Emperor himself might go as far as the holy of holies, but now all barriers have been torn down and all reverence for holiness is dead.'
Source of Descriptive Information
Hedin, S. (1933). Jehol: city of emperors. New York: E.P. Dutton & Company, Inc.