1. Dating back to the late 10th century, Dublin Castle is one of the city's most fascinating buildings. Originally a Danish Viking Fortress in the 930s, it was later strengthened by King John of England in 1204 for defence of the city against (ironically) Dubliners. Today you can walk around the grounds, relax in its gardens and visit 'The Chester Beatty Library', all for free.

2. Dublin is full of parks to retreat when you're looking to get away from it all. The best-known is St Stephen's Green at the top of Grafton St. Others worth checking out are the Iveagh Gardens off Harcourt St, and Merrion Square, just five minutes from Grafton St.

3. Dublin has five national museums and galleries, all of which have free entrance. These include the National Gallery on Merrion Square, the Museum of Natural History next door, the National Museum of Modern Art in the Royal Hospital, Kilmanham and the Museum of Decorative Arts and History in Collins Barracks.

4. If you're planning on visiting either 'Dublinia' or Christchurch Cathedral, rather than buying separate tickets for both attractions, buy a combined ticket for €10.20 that will gain you entrance to both.

5. No matter what time of day or year it is, Grafton St is always full of free entertainment. Sometimes it's musicians aspiring to be the next best thing, other times it's string quartets entertaining passers by, while every now and then it's puppeteers and magicians trying to get a reaction from Dublin's shopaholics. Some are good, some are bad, but all are entertaining.