You got me! I am not that sure, but

来源: 于 2009-08-10 05:54:15 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次
I remembered we started before sun rise (in August), had our breafeast in HuaiRou, arrived by the lake around 1-2pm.

OK, about 7-8 hours.

It is about 100 km.