Man claiming damages after breaking ankle at Hopetoun House ‘bat watch’

• John Cowan claims he stepped off an unprotected ‘ha-ha’ wall and fell down a 5ft drop, breaking his ankle

• A ‘ha-ha’ wall is a common feature of large estates designed to keep sheep off lawns

• Mr Cowan denies suggestions from Hopetoun House Preservation Trust that he deliberately jumped off the wall

John Cowan, 65, said he thought he was walking on a flat lawn in the dark at Hopetoun House, South Queensferry, but stepped off a “ha-ha” wall and fell down the 5ft drop on the other side.

He is suing the trustees of Hopetoun House Preservation Trust, including the Marquess of Linlithgow and his son, Lord Hopetoun, and denies their suggestion that he deliberately jumped off the wall with his five-year-old grandson, then landed awkwardly and injured himself.

“I wouldn’t do it in the daylight, never mind the dark. It’s just too dangerous,” Mr Cowan told the Court of Session in Edinburgh.

The ha-ha is a garden feature often seen on large estates – it provides a physical barrier to keep sheep off lawns without spoiling the view from the house with fencing. On one side, the top of the wall is level with the lawn; on the other there is a sharp drop, with the ground sloping from the foot of the wall up towards the level of the field.

The court heard that the ha-ha at Hopetoun House dated from the 18th century and, according to the trust which runs the estate, had never been known to cause any accidents.

Mr Cowan, of Livingston, West Lothian, and the trust have agreed that he will receive £35,000 compensation if he establishes that his fall was due to the negligence of the trust.

Mr Cowan told the court he and his grandson attended the bat watch with about 20 other people at Hopetoun House in September 2008. They had been advised to bring a torch and wear waterproof clothing and boots.

The group assembled about 8pm, as it was getting dark, and the walk ended at the ranger station more than an hour later. Mr Cowan said his fall happened as he and his grandson then made their way from the centre to the car park. A set of car headlights caught his eye and he decided he must have been going the wrong way, so he started to walk towards the headlights.

He said: “I thought it was just a flat lawn. It was pitch black. I was holding my grandson’s hand and he was holding the torch. He was aiming it in front of us properly. I walked straight off the ha-ha, which I never saw.”

He said the ha-ha had not been illuminated or fenced, and there were no warning signs.

The trust denies liability, and submitted that the accident was Mr Cowan’s fault.

It said night walks were held regularly at Hopetoun and the ranger had given the bat-watchers a safety talk near the ha-ha when it was not yet dark and the ha-ha was obvious. It added that ambient light from spotlights around the house and car park would have meant the ha-ha was still noticeable even after dark.

The judge will give his ruling later.