Traveling in Ireland is great! But take the opportunity to discover the neighboring countries, it's even better. In one shot, I managed to plan two trips outside Ireland: England and Scotland, countries close to Ireland. The airport of Dublin is very close to the city, so it's quite convenient to travel, you can also find there all the companies: from the most high end to the most low cost. The discovery of the world is waiting for you so take advantage of it. However, don't forget your passport if you want to travel in England since the Brexit.
Leeds is a city in England near Manchester, in the north of the country. It is a magical city. I went there to visit a friend who was an exchange student just like me. Leeds is a very student and multicultural city that welcomes young people from all over the world. So it is very easy to meet people even in a 4 days period. The city is full of charm, gothic style, it is full of good addresses, monuments and museums to visit and beautiful arcades which shelter shopping malls all more incredible than the others. I advise you to visit it, especially for its excellent university, on the model of the English universities of Oxford or Cambridge.
Edinburgh was a must for me. Having never been to Scotland, it was my dream to be able to spend at least one weekend in Edinburgh. This city is just indescribable. Unique in its kind, it transports you in another world, in another time. The architecture is breathtaking, the views are impressive and the walks in the city are always very pleasant. Emblem of the Harry Potter saga, this is where J.K. Rollings found most of his inspirations. We find there the magic atmosphere of the novels and we plunge directly into our dreams.