The key is not in Taiping Courtyard. When Fan Xian went to Taiping Courtyard to look for the key, he did not find it. Wu Zhu was certain that the key was in the Royal Palace and that there was a key hidden under the empress dowager's bed. Thus, he was certain that the key was not in Taiping Courtyard.

The key is not in Taiping Courtyard. When Fan Xian went to Taiping Courtyard to look for the key, he did not find it. Wu Zhu was certain that the key was in the Royal Palace and that there was a key hidden under the empress dowager's bed. Thus, he was certain that the key was not in Taiping Courtyard.
The key to opening Taiping Courtyard was the stone in the middle of the lake. As long as the stone was pressed down, the secret room of Taiping Courtyard would be opened.
The filming location of Taiping Courtyard was in Guizhou's Duyun Qinhan Film and Television City.
There was no clear information about the exact location of Taiping Courtyard. The search results mentioned that Taiping Courtyard was a location in the TV series Joy of Life, but did not provide a specific location. Therefore, according to the information provided, I don't know where the filming location of Taiping Courtyard is.
Joy of Life: Finding the Key to Taiping Courtyard
The key to Taiping Courtyard was found in the 149th episode of Joy of Life.
The key to Taiping Courtyard was found in the 149th episode of Joy of Life.
Joy of Life: Finding the Key to Taiping Courtyard
The truth about Taiping Courtyard was not fully revealed in the original novel. In her letter to Fan Xian, Ye Qingmei mentioned that there was a forbidden door hidden at the bottom of Taiping Courtyard's lake. It might be a laboratory. There might be modern high-tech equipment and scientific literature inside. Ye Qingmei also mentioned that Fan Xian might be one of her experiments. The secrets of Taiping Courtyard might pose a threat to Fan Xian. However, the exact truth and hidden secrets of Taiping Courtyard were still unknown. Therefore, there was no clear answer to the truth of Taiping Courtyard and the ending of the original novel.
The truth of Taiping Courtyard was the story between Ye Qingmei and the Qing Emperor. In the novel Joy of Life, Taiping Courtyard was the place where Ye Qingmei had once lived. It was also the place where she met the Qing Emperor. In her letter to Fan Xian, Ye Qingmei mentioned that there was a forbidden door hidden at the bottom of Taiping Courtyard's lake. This forbidden door was where all the secrets were. Ye Qingmei had once lived in Taiping Courtyard. There were memories of her youth with the Qing Emperor and others. Fan Xian was the only person who had succeeded in the experiment Ye Qingmei had mentioned in her letter. His identity and birth involved many secrets. The Qing Emperor had sent heavy troops to guard Taiping Courtyard. Other than not wanting Fan Xian to come into contact with clues related to his mother's murder, it was also possible that the secret at the bottom of the lake in Taiping Courtyard had an important impact on Fan Xian's life. The search results did not provide any specific information about the truth and secrets of Taiping Courtyard.