You may miss the M1851 Wolfsbane, aka Magnum in Resident Evil Village, if you’re not careful. Although it’s not off the beaten path, it is possible to ignore its location and miss out on the most potent weapon in the game.
In short: if you don’t want to miss it after you’ve defeated Moreau and are on your way back from the swamp/water area, you need to enter a locked gate using your new lever. It’s right next to where you entered this area an hour ago.
If you need more information, check out the video below for the weapon’s exact location.