Even from afar, you know that Newgrange is something special. Its white round stone walls topped by a grass dome look otherworldly, and just the size is impressive: 80m in diameter and 13m high. But underneath it gets even better. Here lies the finest Stone Age passage tomb in Ireland, and one of the most remarkable prehistoric sites in Europe.
Soaring over the north end of the centre is Ireland's second-largest medieval cathedral (after St Patrick's in Dublin). This Gothic edifice with its iconic round tower has had a long and fascinating history. Legend has it that the first monastery was built here in the 6th century by St Canice, Kilkenny's patron saint.
No wonder the British army were so reluctant to pull out of Ireland when they were occupying this magnificent space, the oldest army barracks in Europe.
The world-famous library, in the grounds of Dublin Castle, houses the collection of mining engineer Sir Alfred Chester Beatty (1875–1968), bequeathed to the Irish State on his death.
It's easy to spend half a day exploring the attractions and gardens of Birr Castle Demesne. The castle dates from 1620 and is a private home, however for three months in the summer (May, July and August), visitors can visit the main living quarters of the castle.
This remarkably preserved edifice was Ireland's largest Anglo-Norman fortification and is proof of Trim's medieval importance. Hugh de Lacy founded Trim Castle in 1173, but Rory O'Connor, said to have been the last high king of Ireland, destroyed this motte and bailey within a year.
Still the private residence of Henry Conyngham, Earl of Mountcharles, Slane Castle is best known as the setting for outdoor concerts with massive rock royalty names: Bon Jovi and Eminem were here in 2013, while U2, The Rolling Stones, Madonna and Oasis have all set the stage alive over the years Built in the Gothic-revival style by James Wyatt in 1785, the building was later.
Ireland's best surviving example of a 16th-century merchant's house is the Tudor Rothe House. Built around a series of courtyards, it now houses a museum with local artefacts including a well-used Viking sword found nearby and a grinning head sculpted from a stone by a Celtic artist. The king-post roof of the 2nd floor is a meticulous reconstruction.
See how the other 1% lives at Dunsany Castle , the residence of the lords of Dunsany and one of the oldest continually inhabited buildings in Ireland.
The city's famed Waterford Crystal is almost an icon in name only. The first Waterford glass factory was established at the western end of the riverside quays in 1783. Centuries later, after the boom of the 1980s and 1990s, the company fell on hard times and in 2009 was purchased by an American investment firm.
Three spectacular forts stand guard over Inishmór, each believed to be around 2000 years old. Chief among them is Dún Aengus, which has three nonconcentric walls that run right up to sheer drops to the ocean below.
In the town's former cattle yards, a local cooperative runs this tiny but fascinating lace gallery, where you can see lace-making demonstrations and check out exquisite designs.
This 16th-century Norman tower was the summer home of WB Yeats from 1921 to 1929 and was the inspiration for one of his best-known works, The Tower . In a truly inspired setting by a stream, the tower contains the poet's furnishings.