Wildlife Spotting

I was walking in my local park in Denmark and came Actors this tree. I was wondering if it is a Cherry tree, yet I do think the cherries would be ripe by now if that were the case, so I got kind of confused. You can see on the pictures that it does produce some kind of fruit. Furthermore it seems like the tree have two different kind of leaves, one broad and with teeth, another long without teeth. I know it os not a chestnut tree, because there is one of those nearby, and they are getting close to maturation a d the leaves are completely different.