It is recommended to walk or use public transportation in Dublin. The city center is compact and easy to navigate, and most attractions are within walking distance. A day pass for public transportation costs €7, and a taxi from the airport to the city center costs around €30 and takes 30 minutes.
If you have more time, you can visit other landmarks such as the Kilmainham Gaol, the Dublin Zoo, or the Phoenix Park. If you have less time, you can skip the Temple Bar or the Book of Kells exhibition. Don't forget to bring an umbrella and comfortable shoes, and to have some coins for the public restrooms.
Dublin International Airport (DUB) is located 10 km north of Dublin City Centre. It is the busiest airport in Ireland and the headquarters of Aer Lingus and Ryanair airlines.