Monastery Barracks and Monastery Catacombs are two key locations during your first hours in Diablo 2.
While you’re still learning the ropes to fight against the hordes of hell, the last two quests of the first act will task you to find unknown locations during your travels.
Tools of the Trade will take you to the Monastery Barracks, while Sisters to the Slaughter takes place in the Monastery Catacombs. These can be tricky to find, especially if this is your first time with the game.