First, be sure the nuts are edible. You may have a Horse Chestnut, which has
lovely blooms in the spring but produces nuts that are lovely "objets" for
decorating, whether in their spiny chartreuse skin or brown and polished, and
not for human consumption. Kids and the less self-conscious grownups like to
carry them around in their pockets like a worry stone, and I think there are
games you can play with them. I once went over a low wall to pick up a few
lovely specimens in Brno, and almost bumped skulls with a venerable professor
who was also hunting them.