Knebworth House will be opening its doors to brave visitors who aren’t afraid of the dark.

On May 9 and August 16 and 17, visitors will be able to tour the house at night and hear tales of the unexplained.

A spokesman for Knebworth House said: “Due to popular demand we are adding more days of the Ghost Tour & Bat Walk this year.

“In 2017 tickets sold out within days of going live, so if you’d like to come you’ll have to book now.”

Gates open at 6.30pm for 7pm start.

The evenings will include a house tour featuring ghost stories.

Volunteers from The Herts and Middlesex Bat Group will give a talk and will bring in specialist equipment to detect the bats’ high pitched screech, which helps guests to locate them.

Refreshments will be served at Knebworth Barns (soup, a sandwich and hot drinks).

A proportion of the ticket sales will be donated to The Herts and Middlesex Bat Group.

The evening will end at about 10pm.

Visitors are advised to wear warm clothing.

Tickets are £23 per person.

Telephone bookings incur a £1.50 booking fee per transaction.

For more information, visit http://www.knebworthhouse.com/events/ghost-tour-and-bat-walk-may/