Shannon Ireland's airport has been taken over largely as a Military refueling stop .. between the US & The Mid East War theatre.

I'd suggest Dublin Instead ... Its north of the metro area.. you dont have to go in to the Metro area If you choose otherwise ..


Shiphol AMS NL is the easiest airport in my experience of the major international, [lower ticket priced] airports
to cycle into or out of .. as trip start/end.

The NL National rail station is in the lower level of the airport .. too . so get a ticket to Lisbon or any where else from there..