what will you do with it? 15 Acres is a very small holding.
You could join REPS to get some EU grants. Is the land classified as 'disadvantaged'? If so, you might be entitled to more grants if you maintain a certain level of livestock on it. However, that means work as cattle must be looked after ,fed, housed, vetted, disease tested etc.
You could do some research into the feasibility of opening up an open type farm, where visitors would pay a fee to walk the place and see animals in their natural environment. If doing this, you could also have a little coffee shop, play area and at Christmas time, perhaps have a santa grotto. Again, all require work and labour and money.
Could you sell the entire holding as agricultural land? You migth get €20K per acre, again not a huge windfall to change your life and finance your lifestyle to the grave.
Could you sell a site or sites? If so, you should try to get PP, or at least OPP before selling. Could you do a little development of one off sites throughout the holding, creating a little luxury housing estate, but estate is the wrong word to use.
Farming is hard work for little money.