This is Majesty, the largest virgin oak tree in the UK. I'm lucky enough to live near it, its between 800 and 1000 years old, and the trunk is completely hollow! 
I'd forgotten I'd taken this photo till I saw #ThickTrunkTuesday trending..

https://media.mstdn.social/media_attachments/files/109/388/781/630/225/394/original/c0f608d81439e3e7.jpeg