Alnwick Gardens features plants that are deadly, not cool deadly but, DEADLY as in you will die if you mess with them. There are about 100 plants in an area of the gardens that are accessed only by guided tours. Smelling, tasting, or touching any of the plants in this section can lead to death. Even the fumes emitted from them have caused guests to faint. A day ticket to the gardens also allows for access to the poison garden section. So yes there are the less lethal pretty plants that you can touch and smell and the ones in the other that you just look at from a nice safe distance.
Below is an explainer video about the poison garden at Alnwick.
