horse-block

horse-block (plural horse-blocks)

1. A platform or steps used for getting on or off a horse, in modern times, sometimes a vehicle.
   • 1898, Winston Churchill, chapter 4, in The Celebrity:

     One morning I had been driven to the precarious refuge afforded by the steps of the inn, after rejecting offers from the Celebrity to join him in a variety of amusements. But even here I was not free from interruption, for he was seated on a horse-block below me, playing with a fox terrier.

• Merriam-Webster
• Picture