The Temple of Heaven

as you will notice (and count), everything is in nines because they believed that 9 is the most holy number

9 steps to get to the next terrace

Cambria and Ryan (my friend from Guangzhou who happened to be coming to Beijing at the same time I was there)

9 studs by 9 studs on this huge door

Heavenly Centre Stone
As the surface of the uppermost terrace of the circular mound is paved with nine concentric rings of stone slabs, the round stone slab in the centre is called the heavenly centre stone. It is surrounded by 9 stones in the first ring, 18 in the second, up to 81 in the 9th ring, symbolizing the nine heavens. If one speaks standing on the heavenly centre stone, one's voice will become particularly resonant and sonorous.

9 sections in this building as you can see.

To the left is the Danbi Bridge. it is called a bridge because there is a tunnel under it. the middle path is meant for divine gods, the left is for the emperor, and the right is for court officials. At the last gate and largest hall (hall of prayer for good harvest) is one meter higher to symbolize moving up toward heaven.