I think I had up to 120 meters.
This is what the HASP said::
TO Corfu Control Tower
The “Corfu Old Fortress” activity is not approved. A written consent from the management of the Correctional Facility involved is required.
For the rest of requests, I am forwarding you a request for permission/cooperation/coordination of a professional operator for the use of airspace according to the following information and map.
From the perspective of D4, we give initial approval within the framework of our competence. In case of final approval by Corfu Airport Authority, a specific time period will be determined.
Please provide your approval/coordination for the implementation of the activity in accordance with the procedure followed, if required:
the operator to call within a reasonable time before the activity for consultation/receiving permission before the start of the flight,
the operator to call before the start of the flight,
to remain on hold on his GREEK SIM CARD mobile phone during it and
to inform Corfu Airport Authority after its end on the phone: 26610 89824.
And the HCAA gave me an email address for the "Correctional Facility." It has a sofron.gov.gr address.
So it seems to be allowing the flight if I contact this email and also call the airport control tower. But they want me to have a Greek phone number that I could be reached at?