Despite reading and re-reading my fungi book, I haven’t been able to identify these. The one with the cracked top had no stem visible, so without cutting it up I couldn’t get enough information to work out what it was. It seemed a shame to cut down such a pretty mushroom. They’re clearly boletes or closely related – the Boletus family includes the wonderful Cep (Boletus edulis) and the common and edible bay bolete (Boletus badius). Many of this family are edible and good to eat, but some are poisonous, so as always, be utterly sure of your ID before you eat any mushroom.
Here they are anyway; I think they’re rather beautiful.