They may not even ripen fully in Britain, what ones you do get are usually pretty small and don't compare with the imported ones.
We have two 'chestnuts' in Britain, this one, the Sweet or Spanish chestnut and the Horse chestnut(not edible but avidly collected by kids for playing 'conkers').
In Spain they are known as Castanets because of the shape. Or maybe castenets are named after the tree.
There are a lot of them in Britain, not really grown for the nuts, but the wood. They are easilly copiced and grown to about 3 inches thick before being cut. Traditionally this is used for Hop poles, or split into quarters and used for a particular type of fencing known as chestnut palings. or turned into charcoal.
I like to see the full grown tree though, they have a beautfully sculpted bark.