.........or as they are commonly known: Conkers. I went out this afternoon and scrabbled about in a road (between the traffic) near our house to collect them.

You have to get to them before the school kids who generally want them to play the game of Conkers.

Conkers is a traditional children's game in Great Britain and Ireland played using the seeds of horse chestnut trees—the name 'conker' is also applied to the seed and to the tree itself. The game is played by two players, each with a conker threaded onto a piece of string: they take turns striking each other's conker until one breaks. (Info from Wikipedia).

I've added a close crop in the PiP for detail.