Spawn on the ocean shore and travel to the north. At coordinates 300, -550 you will find a huge woodland mansion. There is one chest in the building in the main hall of the ground floor. Inside the chest you will find an Enchanted Book - Thorns III.
When you're done exploring the mansion, go to your west. On your way there you wil see two villages at coordinates -470, -420 and -940, -440. The latter one even has a blacksmith.