Built in 1420 (the 18th year of the Ming-dynasty Yongle Emperor’s reign), this is the main structure of the Fasting Palace complex. As the name suggests, the roof is not held up by beams, but by brick arches. The interior arrangement remains the same as it was during the time of the Qianlong Emperor. There is a horizontal plaque inside says "Reverence for the Supreme Heaven" which was written by the emperor.