Duke University is a university located in Durham, North Carolina.
Isobel Saltzman attended while she was still human to learn about supernatural beings. She also met her husband Alaric Saltzman over there. A Few years later John Gilbert sent a vampire named Damon to her, not knowing that she wanted to be turned. Vanessa Monroe, a new character in Season Two, is shown to have attended here. Damon, Alaric, and Elena came here to find more information on werewolves.
Throughout The Vampire Diaries Series
In Bad Moon Rising, Damon, Alaric, and Elena came here to see Isobel's research about werewolves. Vanessa attacked Elena with a crossbow, but Damon saved her by letting the dart hit him instead. They found out that according to legend a werewolf bite can kill a vampire. Damon also found a book engraved with the word "Petrova" on it, and he knew that Katherine's real name is Katerina Petrova. He gave the book to Elena and they soon left the university.
- Duke University on Wikipedia