Seeing England on this list has probably surprised you, but don't be fooled, danger lurks where you'd least expect it. As with Acapulco, this garden is beautiful, yet potentially deadly. At first glance, the luscious roses, spectacular water features, and immaculate lawns provide you with a false sense of security. Then you're met with a sign that brings you straight back to reality: "These plants can kill you."
Alnwick Gardens is well known as the 'poison garden' and is home to more than 100 deadly plant species. With killer plants including Conium Maculatum, Strychnos nuxvomica, and Atropa belladonna, it's no wonder this deceptive garden is the most dangerous of its kind in the world. The garden also plays host to a crop of coca leaves, the main ingredient of the infamous narcotic, cocaine. Enter at your own risk!