I always love the way councils always assume stuff like this - did they bother to ask?
This may well be a bad sign, since if they are right, the landowner may have plans for it.
First thing is to make contact with the landowner and fidn out what if anything is planned. You may not want to say what you think the site is until you know this person better.
At the end of the day, the future of this site is 98% determined by the landowner. No work of any sort can be done without hgis/her consent. Including archeological investigations.