Legend says that Gulaogang in Yicheng, Hubei, was once the Goulou Street of the ancient capital of the State of Chu. It was here that King Ping of Chu, upon ascending the throne, executed Wu Zixu's entire family. Later, Wu Zixu escaped to the State of Wu. Anticipating that Wu Zixu would surely return for revenge one day, King Ping took precautions early. He summoned a thousand skilled craftsmen from across the kingdom to construct an underwater palace beneath a lake for him. This palace was filled with secret passageways and hidden mechanisms, allowing him a place to hide should disaster ever strike. The construction took ten years to complete. Once finished, to prevent the secret from leaking out, King Ping devised a deadly scheme to silence the craftsmen.
One day, King Ping issued an imperial edict, declaring a celebratory banquet would be held in the underwater palace to reward the craftsmen with gold, silver, and treasures. Of the thousand craftsmen, nine hundred and ninety-nine arrived—only one carpenter was absent due to family matters. However, poison had been secretly added to the food and wine, and all nine hundred and ninety-nine skilled craftsmen were murdered by King Ping.
Many years later, Wu Zixu indeed returned at the head of an army from Wu, diverting the waters of the Man River to flood the capital of Chu①. Legend says that after breaching the dikes, Wu Zixu led the charge, dragging a spade, while a towering wave, several zhang high, surged powerfully behind him. The flood entered through the west gate of the Chu royal city and rushed all the way into the Forbidden City. Seeing that resistance was futile, King Ping hastily fled to the underwater palace.
Wu Zixu pacified the people and reorganized the government, but since he had not yet captured King Ping, his heart remained unsettled, and he searched tirelessly everywhere.
Meanwhile, the carpenter who had narrowly escaped death heard that Wu Zixu had returned and quickly went to find him. That day, near the Forbidden City, he encountered Wu Zixu and rushed forward, shouting, "General Wu! General Wu!" Wu Zixu turned and asked curiously, "How do you know I am Wu Zixu?" The carpenter replied, "King Ping of Chu once ordered your arrest and had your portrait drawn and posted everywhere. Who doesn't recognize you?"
Wu Zixu said, "Do you have something to tell me?"
The carpenter answered, "I know you must be searching for King Ping of Chu. I've come to inform you. I know where he's hiding." The carpenter then recounted to General Wu the entire story of building the underwater palace and offered to personally lead Wu Zixu to capture him. Deeply moved, General Wu bowed deeply to the carpenter. Together, they made their way to the underwater palace.
The carpenter opened one hidden door after another, and finally they discovered the corpse of King Ping of Chu, who had suffocated to death inside.
Upon seeing the body, Wu Zixu's hatred flared. He dragged the corpse up from the submerged palace and hauled it all the way to a platform west of the city, where he exposed it to the scorching sun. He lashed it three times with his horsewhip. Suddenly, the corpse of King Ping of Chu knelt upright, its eyes slightly opening, as if pleading for mercy from General Wu. Later generations named the lake "Lao Shi Hu" (Corpse-Searching Lake) and the platform where the whipping took place "Shai Shi Tai" (Corpse-Exposing Platform).
① Historical records state that it was the Qin general Bai Qi who diverted the waters of the Man River to flood the Chu capital. However, local legend attributes this act to Wu Zixu.