Will My Garmin Nuvi 2405/2505 Work In Ireland?

The short answer is YES. GPS works nearly everywhere on the planet. Assuming you're planning on using it for getting around on the roads, you would most likely need to purchase an additional map pack for your Garmin (if you have a 2555 purchased in the US, it's unlikely it has this region installed already, but please check by zooming out and scroll across the Atlantic Ocean to Ireland, then zoom in. If you see nothing but tan or green with no roads or labels, your Garmin does not already have this map pack. The map itself comes on a microSD card (small memory card about the size of a fingernail) and you insert it into the slot on your Garmin. The following map pack works for the UK and Ireland only, so if you're visiting continental Europe or any other countries, you would need to buy map packs for those regions too. Here is a link to the UK/Ireland map pack: https://buy.garmin.com/en-US/US/maps/on-the-road-maps/city-navigator-nt/city-navigator-europe-nt-u-k-ireland/prod8424.html (you may be able to find it for less on other online shopping sites or even in stores like Best Buy--they often clearance them out). Be sure to allow enough time before your trip for the map pack to be mailed to you, although you may be able to download it from Garmin's website as well. Have a great trip!