The National Museums of Ireland are, for the most part, located in Dublin - though you may have to go further afield to experience country life. All four of them offer collections that should be considered for your itinerary. Depending on taste and interests, obviously. Here is the basic information you need to know.
National Museum of Ireland - Archaeology
Upon entering the National Museum in Kildare Street you will be struck by the grand cupola in the entrance hall. The building itself is an attraction - but the treasures contained within are priceless.
You will be confronted immediately with gold - hoards of gold actually, dating from prehistoric times and buried or hidden for ages. The rich ornamentation and subtle craftsmanship has to be seen. Most visitors will, however, turn right and enter the treasure chamber. Celtic and early medieval artifacts are on display, several of them having gained an iconic status. The Tara Brooch, shrines, croziers and other church paraphernalia are covered with unbelievably detailed ornaments. Hidden away in a corner the rougher Sheila-na-Gig glares in contrast.
One of the newest exhibitions is "Kingship & Sacrifice", a presentation focusing on four bog bodies of uncertain origin, including iconic Clonycavan Man. Better preserved than Egyptian mummies, these prehistoric noblemen were found during peat harvesting - one actually became part of the harvest from his waist down. This is the nearest you will ever come to face Celtic men from the Bronze Age. Thoughtfully arranged with moody lighting, the exhibition explores the (possible) reasons why these men ended up dead in a bog.
Also recently overhauled for the anniversary of the Battle of Clontarf was the splendid exhibition on Viking life in Ireland.
Address: Kildare Street, Dublin 2
National Museum of Ireland - Decorative Arts & History
Upon entering the massive Collins Barracks courtyard, you will first have to identify the museum entrance on the left-hand side. From here you have access to four floors of exhibitions - ranging from "Irish Country Furniture" to coins, from silverware to clothing and from scientific instruments to "Irish Period Furniture". This eclectic mix is augmented by a glimpse into the Aladdin's Cave of storage, here you will find even Samurai armor ...
There are noteworthy exhibitions on the Easter Rising period, definitely thought-provoking and lacking blatant, uncritical hero-worship, and on Ireland's military history in general - from the "Wild Geese" to UN service, including a rare Landsverk tank, armored cars, planes and weapons used by the warring Lebanese and Palestinian fractions.
A car park is available, but the easiest access is by using the LUAS tram.
Address: Collins Barracks, Benburb Street, Dublin 7
National Museum of Ireland - Natural History
The ground floor of the Natural History Museum, also affectionately called "the Dead Zoo" has a comprehensive display of Irish wildlife, from the skeleton of the extinct giant Irish deer to the rabbits introduced by the Normans. The other floors are devoted to international fauna, jumping between continents with reckless abandon. You will see elephants, a rare Tasmanian Tiger and a polar bear shot by Irish explorer Leopold McClintock (with the fatal entry wound still clearly visible).
Most of the mammals and birds are preserved through taxidermy. Victorian style. Which makes for some truly grotesque creatures due to the simple process followed. A sizeable number of exhibits bear little more than a passing resemblance to the living animal. Add the fact that time, sunlight and insects have taken their toll on several specimens and you will understand why this museum is not one of the top ten attractions of Dublin. The fish and other animals preserved in alcohol lend the museum a certain sideshow feeling with their ghostly pallor.
That said I have to say that some displays are fascinating, the family groups done up by Williams and Son for instance, or the huge basking shark and moonfish caught in Irish waters. And the huge number of glass animals designed by the Blaschka family from Leipzig deserves a good look too.
Address: Merrion Street, Dublin 2
National Museum of Ireland - Country Life
This museum focusing on the rural aspects of life in Ireland has a host of interactive displays and screens, including actual video footage of traditions that are in danger of becoming a distant memory. Also featured are traditional crafts like harvest knots, wickerwork, spinning wheels, and artifacts from bygone days like boats, clothing, and all sorts of hand-operated machinery.
Address: Turlough Park, Castlebar, County Mayo