CONKERS.

Otherwise known as Horse-Chestnuts. The leaf stalks leave a scar on the twig when they fall, which resembles a horse-shoe with nail holes. ( I will look for this next time I am nearby)  This could explain why they are called horse-chestnuts and are ground up to relieve horses of coughs. Other uses are, additives to shampoos and some medical uses for humans. In WW2 people were asked to collect them to help the war effort and donate them to the government. Their starch was used in the production of Cordite to replace gunpowder as a military propellant. The game of Conkers was first recorded on the Isle of Wight in1848. A hole was skewered through the conker and a length of string threaded through. The object then was to smash your opponent's conker. For many years, the pub on Midsummer Common, The Fort St George, held an annual competition, but it has been stopped by 'elf 'n' safety although nobody ever got hurt apart from a few bruised fingers maybe. I actually collected a bag full as I read that they deterred spiders and I have placed them by doors and windows and in the bathroom. I have previously found  couple of huge spiders. Hope it works !