Where is it?

Alnwick Poison Garden. In the grounds of the Duchess of Northumberland’s family home, Alnwick Castle, Northumberland.

Why do you go there?

To see plants that can literally stop your heart. For the otherworldliness, and dare I say, thrill of entering the poison garden, knowing that all of the plants within it will make you very sick and some will even kill.

Helleborus niger - common name Christmas rose - contains a cardiac toxin called helleborine which first slows down and then stops your heart. And Digitalis purpurea - foxglove - contains cardiac glycosides and, in particular, digoxin which if ingested can cause cardiac arrest.

Then there is Ricinus communis, the castor oil plant seen in municipal planting schemes in parks all over the country. Not many people know that the seeds are the part that produces the oil, but they also contain ricin, one of the deadliest poisons in the world.

How often do you go?

Not as often as I’d like because I live in Brighton.

How did you discover it?

On a two-week driving holiday in a rusty and very temperamental VW campervan. We were en route from London to Edinburgh with two small children, stopping wherever and whenever we fancied.

In Northumberland, we chose Alnwick Castle and being the plant-obsessed person in the family, I insisted we visit the gardens.

The poison garden with its skull and crossbones “These Plants Can Kill” caution at the entrance, turned out to be the highlight of the day, especially for my pirate-obsessed kids.

Who do you take?

I like to take friends so I can wow them with my plant knowledge because, to be honest, none of them would have any idea I was mispronouncing the Latin names.

I’d love to take Eustacia Rose, Professor of Botanical Toxicology, the protagonist in my debut novel Devil’s Breath. I bet she would have a few hair-raising anecdotes.

What do you take?

Inspiration. The first seed of an idea for the Professor Eustacia Rose Mysteries germinated at Alnwick. I loved hearing the gory death by poison stories, learning about antidotes and plant folklore. They got my creative juices flowing.

What do you leave behind?

The tour of the poison garden is excellent, and the guide is enthusiastic and funny. I always try to show my appreciation of their incredible knowledge and encourage my friends and family to do the same. So, I suppose, I leave behind my thanks.

Sum it up in a few words.

Thrilling. Shocking. Fascinating. A little bit of gruesome and a lot of marvellous.

What other travel spot is on your wish list?

I’d love to travel around the top of Myanmar and meet the indigenous Karen people, so they can teach me about their jungle poisons, antidotes, medicinal herbs and traditional customs. Then perhaps I’ll set a Professor Rose Mystery there.

Devil’s Breath by Jill Johnson (Black & White Publishing, £14.99), is out now