A city of Klingon history, conquered by the forces of Emperor Sompek, who ordered it burned and everyone within it killed.
Tong Vey is an ancient Klingon city mentioned in the Deep Space Nine episode Rules of Engagement.
During the hearing over Worf's destruction of a Klingon transport, the advocate Ch'Pok brings up a holosuite programme Worf had run the day before the battle. It recreates the fall of Tong Vey, in which Sompek took the city and then commanded that it be razed and its people put to death.
Worf admits that he played the general and gave that order. Ch'Pok uses this to argue that Worf was in a mood for slaughter, part of a case built to discredit the Federation.