The odd things you see above are medlar fruit, on the left showing its gnarly bottom - quite literally in fact as it's colloquially known by the endearing term of "dog's arse" or "open arse", medlar being the politer term imported from the French.
This fruit was popular in Victorian times but is little seen today. It is unusual not just in its looks, but because it requires 'bletting' before eating. This involves allowing frost or simply storage over time to somewhat rot the fruit, whereupon its insides turn gooey and edible. The fruit is hard and acidic before bletting.
Thanks to Sheila for the picture and the introduction to this fruit that I had personally never heard of before.