Can anyone identify the oak species these acorns come from?
Here are some pics of the leaves and bark
Gardening & Landscaping Stack Exchange is a question and answer site for gardeners and landscapers. It only takes a minute to sign up.Sign up to join this community
There are only a limited number of Oaks which produce this mossy cap at the bottom of the acorn - those that do are listed below, but without leaves, it's next to impossible to be certain which it might be:-
Quercus suber, maybe, the Cork Oak;
Or Quercus cerris (Turkey Oak, known as European Turkey Oak in countries outside of Europe);
And possibly Quercus hispanica 'Lucombeana' - can't find an accessible online image of this one's acorns, though there is one in my tree directory. Roger's Trees and Shrubs has a good picture, but their site is down currently.
Of these, Turkey Oak is widespread in the UK and Eire, and is the most likely candidate.
UPDATE - The images you've added, particularly of the grey, fissured/ridged bark, confirm the ID as Quercus cerris (Turkey Oak).
My guess without the leaves or bark would be Quercus robur; the English Oak or the Common Oak or the pendunculate oak.Quercus robur