What is a ha-ha?

The following is an excerpt from my new novel Improper Vow:

            “Oh, bother!” Diana said.  “I think she needs a run.”

            “A gallop will do,” Vivien suggested, not liking anything that approached racing, an unladylike pursuit.  It was all very well for the wealthy and fashionable Lady Diana to indulge in exploits, but not an out-of-the-way miss like Vivien Montgomery.

            Diana turned her horse off the path toward the boundary of the park, far in the distance.

            “Let us keep to the path, don’t you think?” Vivien added.

            “Not if you want to jump the ha-ha,”  Diana said. 

            “I don’t.”

            “I’m persuaded that Garnet is ready to try it. Especially if she is following Thor.”

            The ha-ha was a wall erected many years ago to separate Hyde Park from Kensington Gardens. To an approaching horse, the wall appeared less than two feet, a modest hop for a highbred mare like Garnet. But the other side was a steep drop-off, and capable of unseating the best of riders.

             “I have no intention of jumping anything. And neither should you,” Vivien warned. “Your sidesaddle is not stable enough.”

            “Then I shall go first,” she shouted, allowing Garnet to turn toward the serpentine lake and the wall beyond it.


            But the mare was rapidly retreating from sight. Vivien felt sick as she spurred Thor after her. If there was an accident, she would never forgive herself.

           Nor would Lord Northam.

            Thor covered the ground smoothly, his gait elongated and gaining on the much younger Garnet, who was by now fighting Lady Diana’s hold on her bit, her tail wringing like a flag and slowing their progress considerably. Vivien’s heart beat was so rapidly, she thought she might actually find out what it meant to have the vapors. 

            “Diana, do not be so foolish!” she called.

            To her relief, she saw the mare come to a halt. And then she saw why. Northam’s face was a mask of fury as his great bay galloped up.  Although she had not been at fault, Vivien still felt like a naughty schoolgirl. She must have looked guilty, for his lordship was scowling at her.  Thor didn’t help matters, acting as though he were at fault as well, flicking his ears back and forth worriedly.        

—-Jumping a horse over a ha-ha can be unsettling, at least for me.  Resembling a drop fence in cross-country terms, the jump is quite a ride if you are not prepared for the steep descent.  As Vivien, the heroine of my novel knows, one shouldn’t try it with a side saddle, because a fall while negotiating such an obstacle can result in severe injury to either rider or horse.  At a minimum, a successful jump over this fence puts a lot of stress on the horse’s front legs.  She’s also aware that 

cross country drop fence

the horse has to really trust his rider, because he cannot see the the landing until he is about to take off. 

 Queen Caroline had one installed to separate Kensington Gardens from Hyde Park in 1728.