Dublin, Ireland is a wonderful city to visit, with its historic sites, literary bent, and wonderful pubs and restaurants. It’s also a great city for runners. Since Dublin is so compact, many of the iconic runs are easily accessible from the center city. Highlights include Phoenix Park, and some nice runs along the River Liffey and the canal towpaths. There is also some wonderful seaside running just north of Dublin, toward Clontarf and Howth, around Howth, and in Malahide. South of Dublin, within 1/2 hour by train or car, are lovely waterside runs in Dún Laoghaire and a fabulous path from Bray to Greystones.
There’s not much running of note near the airport (10 miles from city center), but if you have a car, it’s only 10km to Malahide and 16km to Howth.
Dublin does not have a subway, but it has a fairly extensive bus and tram system, and some rail lines toward the suburbs. The DART is a nice train along Dublin Bay, heading both north and south, providing easy access to some great running spots.