This is Moonflet's churchyard. Here is where the story starts. John found the crypt and Blackbeard´s locket. He was terrified thinking about Blackbeard´s ghost but the ambiton of finding the Diamond was enough to give him the necessary courage to go on with his adventure.
John entered into the crypt and opened Blackbeard´s tomb to look for the Diamond but unfortunately it was not there. Instead he turned up with the locket of Colonel John Mohune. The diamond was not inside the locket either. When he tried to leave the crypt, he realized that the hole has been closed by Ratsey. He didn't have any other choice than to stay there that night.