On Wangxi Mountain located near Tang Manor.
Even without reading Grandfather Han's monthly journal, Tang Ling knew that he must go to the mountain for the final answer because it was the only mountain ridge in Wanghe County.
Tang Ling headed out without looking back, but he also did something for the innocent souls that had died under Grandfather Han's cruelty. He left a letter saying that there were a dozen bodies under the pond in front of Tang Manor and expressed his hope that they could be dug out and be given a proper burial.
The exact location was not stated in Grandfather Han's monthly journal though, so Tang Ling made a deduction based on all sorts of clues and evidence.
In short, it would be troublesome to deal with that many bodies, so the best way to deal with them would be the pond in front of the manor.