A garden in Alnwick Castle in Northumberland, England is locked behind black steel doors. People coming in are required to wear protective clothes and gears. What is inside this garden?

The garden is known as the Poison Garden, a brainchild of the Duchess of Northumberland. It has almost a hundred kinds of deadly plants such as laurel, deadly nightshade, hemlock, and hogweed.

Watch this video and take a tour of the garden with Trevor Jones, the head gardener of the deadliest garden in the world.