Dublin is a small city. Despite its high per-capita GDP, unlike Singapore or Tokyo, the city feels fairly low-key and more of a middle-affluent country.

The official languages are Gaelic and English. To preserve Gaelic, all laws are officially passed in Gaelic!

Day 1

The city of Dublin is not huge. You can walk everywhere and even skip public transport.

I would recommend starting with a walking tour that gives you a great idea of the city. Rick Steve has great guides as well.

The Spire which cost almost 5 million Euros to build is visible from almost every part of this city.

The Trinity College campus is open to the public as well.

The Dublin library inside the college has a 25 € tour where one can see an 800 AD book Book of Kells. Check the book online before you go on the tour.

The temple bar is of course fairly famous and hard to miss at night. There’s even a live cam feed of it.

Day 2

The city of Dublin is divided into North-south sections by the Liffey River. And there are multiple pedestrian bridges on it.

The south side contains historic monuments like Dublin castle.

The north side contains the monuments devoted to the Irish struggle for independence against Britain like the Parnell monument and Garden of Remembrance.

Note:

1. You can take the 10 € bus 784 from Dublin airport and go from/to Dublin.
2. Credit cards are widely accepted, so, no cash (Euro) is required. The only exception I noticed was local (intra-city) buses that required Euro coins for tickets.