15 kilometers.

1. First, there are three stations from Zifeng Building to Ziyue Plaza, the total distance is 15 kilometers.

2. It is 4 kilometers from Zifeng Building to the No. 14 platform and takes 7 minutes.

3. Then go from Route 14 to Route 21 for 9 kilometers. It takes 15 minutes by bus.

3. Finally, go from No. 21 to No. 32 and enter Ziyue Plaza for 1***2 kilometers.