Ryan5252 means that the exemption of the 500ft rule granted while taking off and landing from a licenced aerodrome does not apply when doing PFLs.
There is no requirement that I am aware of that states the TO/LDG are to be made from a licensed aerodrome.
However, the CAA have stated that they would take a pragmatic view about prosecution under such circumstances.
I'll let you chance it!
Cheers,
Ryan