I think you've got a horse chestnut tree.
The nuts are well known for their "bitter flavor", to humans, and were dried for horse and cattle winter feed.
Description is here :
http://www.botanical.com/botanical/mgmh/c/chehor58.html
That wild vs. cultivated isn't really true when it comes to chestnuts, before they were put on the brink of extinction American chestnut trees were noted for their sweet apple-like flavor.
Nowadays, with the chinese variety and the european variety, I find them mealy and bland but every so often I get a few that have a surprisng amount of underlying sweetness.
There are chestnut bread and cake recipes, though I find them way over-rated, as well as one desert, with alot of whipped cream, that's tolerable.
Like 51 said you roast chestnuts and as long as you don't intend to keep them over the winter (or ship them across an ocean) they don't have to be aged.