I can't remember a ruined abbey... but I have a bad memory for locations.
The place is called Murton Park (or the Yorkshire museum of farming, whichever is on the AA roadsigns that direct you to it...). A lot of it consists of farm machinary from different historic periods in barns - old combined harvesters etc. There is a steam train there as well for no readily discernible logical reason. Further back in the site there is a Danelaw (for those that don't know - Danelaw was a period when parts of the UK were ruled by the Danes) village (which is basically wattle and daub huts with some fields with live animals in them), a Tudor inn and a wooden Roman fort (which actually looks like it was made of fence panels from B&Q but we reckon that is not too different to how they made them originally...). Worth a look around if you are into seeing how different periods in history lived.
The village, inn and fort are often used by re-enactment groups (in fact, they were all built by re-enactors and maintained by them) and are also frequently used by schools to do 'history empathy days' where children spend the day pretending to be a Roman soldier and get bawled at by a Centurion and drilled into different formations.
They are also sometimes used by LRP groups and I have hired it a few times to run events (where it was discovered how hard it really was to attack a Roman fort, unless you are prepared to climb over the wall as one person did...) and the management were always amenable to talking to people interested in history.
As for the other event, send me a PM and I can send you more details.