Trinity College
Ireland's premier university was founded in 1592 by Elizabeth I, who hoped its distance from the European continent would save its students from being 'infected with popery'. Officially called the University of Dublin, the 16-hectare (40-acre) institution was the sole preserve of Protestants, and even when this restriction was lifted in 1793, the Catholic Church forbade its young from attending. This restriction was only wholly lifted in 1970!
 
The grounds of Trinity College are great to explore independently, although the College does run organised tours that are also recommended. Either way, the focus of any trip to the university is a visit to the famous Book of Kells, a magnificent 1200-year-old illustrated manuscript, and one of the oldest books in the world. About half a million people a year come to see the book - usually opened to an illustrated page and a page of text - so expect long, long queues in the peak tourist season. Once you've seen the book, don't rush off - there are other interesting buildings open to the public and worth visiting, including the Library Long Room, the Reading Room and a 45-minute audiovisual display called The Dublin Experience. Trinity College is located south of the River Liffey, near Pearse Station.

Temple Bar
Officially regarded at Dublin's 'cultural centre', the Temple Bar area could just as easily be dubbed 'Ibiza in the Rain'. The huge congregation of pubs and bars turn this contained district into a party zone practically every night of the year. The term 'bar' could easily refer to the single, uninterrupted drinking establishment this area becomes on summer nights, but actually is the historical term for a riverside walkway. This is not to say that Temple Bar is merely a blurry-eyed, sodden paean to alcohol overconsumption; the area has experienced an extraordinary rebirth in recent years, with groovy bars, restaurants and trendy stores offering a one-stop district for Dublin's young inner-urban hipsters.
 
Before making yourself too comfortable inside a glass of Guinness, head over to the western perimeter of Temple Bar and stroll down Dublin's oldest thoroughfare, Fishamble St (if you do encounter an ambling fish here, you're already drunk and should just check yourself into the nearest pub for further mistreatment). Fishamble was originally a Viking enclave, and dwellings from this time were dug up in 1980 - follow the symbols in the pavement to reach a mosaic outlining the results of the excavation. Another 'old' milestone can be found in Parliament St where Read's Cutlers at No 4 lays claim to being the city's oldest shop, having been in operation for 240 years. Eustace St has a number of historic buildings (twice as many when you're no longer sober), including the Presbyterian Meeting House which dates from 1715. The maze of streets comprising Temple Bar is sandwiched between Dame St and the river, west of College Green and the Bank of Ireland.

Phoenix Park
Twice the area of New York's Central Park at a massive 700 hectares (1750 acres), Phoenix Park is not your average city park. Not content at being replete with a zoo, a castle, sports pitches, and lakes and gardens, the park has also at times played a prominent part in the political history of the city - in 1882 it was the site of the murder of the then British chief secretary for Ireland, Lord Cavendish, by the Irish nationalist group modestly called The Invincibles.
 
Apart from its natural greenery and outdoor facilities, the park's showpiece is the Dublin Zoo. The Zoo, which is being given a much-needed facelift over the next couple of years, has a significant lion-breeding programme and a well-regarded exhibit on African reptiles. In the northwest corner of the park is its visitors' centre and next door to this is Ashtown Castle, a four-storey tower-house built in the 17th century. The Aras an Uachtarain lies in-between the castle and the zoo and is the official residence of the Irish president. All can be reached by bus No 10 from O'Connell St, or bus No 25 or 26 from Abbey St Middle.

Dublin Castle
Dublin Castle lies on Cork Hill next to Temple Bar in the heart of the city. The original Norman structure was assembled in the 13th century as a heavy-duty repository of British power, although only the Record Tower survives from the first construction. The castle has at various times been under siege (1534), used as a prison (late 16th century), and nearly destroyed by fire (1684), and is now occasionally used for government conferences as well playing host to hordes of snap-happy tourists.

As well as having a whole lot of dignified viceroy eyes following them as they go through the Portrait Gallery, and trying to refrain from eating on the floor of the Wedgewood Room, visitors will be treated to the lively Gothic interior of the Royal Chapel and the expansive collection of Middle Eastern and Asian books and other artefacts in the Chester Beatty Library. The castle is located behind the City Hall on Dame St.