Anyone having fun with terrain near Dublin?

I do use the MK EIDW Dublin airport, but have a lot of amusement at FL260 amd below with terrain warnings from the GPS. Well, both of them actually. I wonder if anyone else sees any local difficulties? I havent mentioned the GPS platform so that I can get a balanced understanding of where this anomaly might lie. I never realised that when going feet wet on an easterly heading that some Surtsey like island was already well past 12,000 feet.

Thanks in advance,

Magic.