Ignorance of the law is no defence, right?

[royfellows]

So even doing something entirely underground in a SAM could catch you out.

No disrespect but I have already confirmed this in a different thread, as has another.
Cwmystwyth is a SAM and consent from CADW had to be obtained for our (entirely) underground works.

I understand that it was a 'first', at least in Wales.

 

[Ed]

MoD and Coal Authority might not be land owners but have some responsibility and/or be tenants or have special rights ie via Acts of Parliament

 

[Bob Mehew]

?  Landowner Permission

?  Confirmation that the land is owned in ?Fee Simple?

A tenant is not the landowner. In any event, point "2" overrides any tenant.

The complexity of land ownership and owenership of rights associated with land cannot be simply summed up.  But as I understand it, the import of "Fee Simple" means that if the land is not so owned, then other persons have rights which could be impacted on by digging.  The simplest example is if the right to extract limestone has been sold by the land owner to another person.  That other person could well consider the risk of granting permision to dig with the prospects of opening new cave which then creates such a stir to cause it to become either a show cave or a SSSI is such that they refuse to give permission.  That is because they fear a show cave or SSSI would knacker their right to extract limestone. 

Roy understands this area much more than I do but I would suggest adding to "Confirmation that the land is owned in ?Fee Simple?" to something like 'or obtaining permission from all interested parties'.  What makes it worse is that often the right was sold centuries ago and is not in modern records.