Roanapur is the fictional city of Black Lagoon in Thailand where Lagoon Company operates, Alongside Hotel Moscow, the Hong Kong Triad, the Colombian Cartel, the Mafia and other crime groups. Roanapur is considered by many, including its inhabitants, to be a den of crime and corruption.
After the Vietnam War, Roanapur became a city where deserting soldiers and prostitutes ran wild. It was explained by Mr. Chang that thirty-five years before the start of the series, Roanpur was a dying port town. Chang goes on to state that Roanapur is a criminal center that was made by criminals cooperating for single common interest.
While Rock is examining a map during episode 2 of season 3, Roanapur is shown to be in the geographic location on or very near Trat, Thailand.
Roanapur is an old Thai port in southern Thailand, where the deserters and the losers of the Vietnam War took refuge and were joined by the worst villains and criminals of the planet. Prostitutes, drug-addicts, mercenaries, killers, and psychopaths of any nationalities compose the population of Roanapur.
Yellow flag Bar
The Yellowflag Bar is the property of Bao. It is in this disreputable place that the worst criminals of Roanapur pass time between missions.
The Buddha statue
In the entrance of the gulf which leads to the Roanapur port, there is a statue in ruin representing Buddha, which is "supposed to bring peace to the world"
The Slip Knot Bridge
Roanapur is accessible from the continent thanks to a bridge. In the extremity of this bridge, there is a slip knot. This rope warns visitors who want to go to Roanapur they have to expect everything if they enter the city.
The most well known groups in Roanapur are the Rip-off Church, the Triad, and Hotel Moscow. Some less well known groups are the Italian mafia, the Colombian cartel, an unnamed crime syndicate, and the CIA.