James T. Kirk went here to gather information in 2293 after Hikaru Sulu and several members of the USS Excelsior crew were captured by Beta Promethean pirates. At the time, the Deltan Duo were performing there.
After Kirk and his former command crew rescued Sulu and the Excelsior crew members from captivity, they attended a party at the Flag and Grog. Also at this party was the Federation President and a number of Starfleet officers. (TOS novel: The Fearful Summons)