Ireland has a wealth of impressive historical monuments. In Ireland there are four types of megalithic tombs: court cairns, passage tombs, wedge tombs and portal dolmens. Megaliths are not unique to Ireland - they can be found in western Europe, in Spain, Portugal, western France, Denmark, Ireland and parts of Wales and Scotland. Nevertheless, with over 1500 recorded megalithic tombs still in existence in Ireland, it is an important aspect of Irish history.

Court Tombs (Cairnes) were rectangular burial chambers. They are distinguished by their oval-shaped court yard without a roof. Large slabs of rock were used to make walls - these were once covered by another large slab to create a roof. They usually had two functions: the chambers to serve as a tomb and the court yard to accommodate a ritual. Objects were often buried with the deceased as the first megolithic farmers of this time believed in life after death. Most court cairns appear to have been built in the early Neolithic period, around 3500 BC, but many remained in use until as late as the Bronze Age transition, c. 2200 BC.

There are about 300 of this type of tombs in Ireland. These tombs have an open unroofed, east facing entrance court which leads into a number of chambers. There could be maybe four chambers in total. Each of these chambers can contain inhumations and cremated remains. The chambers on the inside are roofed by the method of corbelling. Orthostats {Huge standing upright stones} are put into position. Then reasonably flat rocks are placed on top of each of the two orthostats. Two more flat rocks are slid barely half - way over the preceding rocks. This continues until a pair of flat rocks nearly touch each other. A capstone is placed on top so the whole structure looks like a hut. Around these chambers is a reasonably low dry stone wall with orthostats at the extremity. These tombs are sometimes called a lobster - claw cairn. They generally average 23 - 24 metres. They are usually rectangular. They faced east towards the rising sun. So the soul met its creator. The general theme is that all the tombs face east.

Good examples of court tombs, which have been partially reconstructed, can be seen at Creevykeel, County Sligo; Annaghmare, County Armagh; Magheraghanrush, County Sligo; Creggandevesky, County Tyrone; Ballymacdermot, County Armagh; Cohaw, County Cavan and Tullyskeherny, County Leitrim.

A passage grave or passage tomb consists of a narrow passage made of large stones and one or multiple burial chambers covered in earth or stone. Megaliths are usually used in the construction of passage tombs, which usually date to the Neolithic. Those with more than one chamber may have multiple sub-chambers leading off from the main burial chamber. One common layout, the cruciform passage grave, is cross-shaped. Sometimes passage tombs are covered with a cairn, especially those dating to later times. Not all passage graves have had record of bodies being contained in them.

Passage tombs of the cairn type often have elaborate corbelled roofs rather than simple slabs. Megalithic art has been identified carved into the stones at some sites. The passage itself, in a number of notable instances, is aligned in such a way that the sun shines into the passage at a significant point in the year, for example at sunrise on the winter solstice or at sunset on the equinox.

Passage graves are distributed extensively along the Atlantic façade of Europe. They are found in Ireland, Britain, Scandinavia, northern Germany and the Drenthe area of the Netherlands. They are also found in Iberia, some parts of the Mediterranean, and along the northern coast of Africa. The earliest passage tombs seem to take the form of small dolmens. In Ireland and Britain, passage tombs are often found in large clusters, giving rise to the term passage tomb cemeteries.

There are many tombs of this type in Ireland. Examples include Newgrange, Knowth, Dowth, Loughcrew, Fourknocks, Carrowkeel and Carrowmore.

A wedge tomb is a type of Irish chamber tomb. They are so named because the burial chamber itself narrows at one end (usually decreasing both in height and width from west to east), producing a wedge shape in elevation. An antechamber is separated from the burial area by a simple jamb or sill, and the doorway generally faces west. A distinguishing characteristic of wedge tombs is the double-walling of the gallery. They were often covered by cairns, which could be round, oval or D-shaped, often with a kerb to revet it. More are low sized, usually about 1.5 meters high, and are generally found on mountain sides, about three-quarters the way up.

Wedge tombs were built between the Irish late Neolithic and middle Bronze Ages (about 2500 to 2000BC). Today, between 500 and 550 known wedge tombs survive in Ireland, and are found predominantly in the west and north west of the island.Their sloping roof and narrowing walls at one end produce their characteristic wedge shape.

Good example of a wedge tomb is Glantane East Wedge Tomb, County Cork and the tomb at Lough Gur, a wonderful site in County Limerick with many ancient remains, including the Great Stone Circle, the biggest in Ireland, Pookauncorrin in County Kerry and Cabragh Wedge Tomb in County Sligo.

Portal tombs appear to have developed from court tombs. They are so-called because of the prominence of the doorway. As well as other vertical stones, they have two very large stones forming the doorway and an enormous stone, which not only covers the doorway but also covers the whole tomb. This 'capstone' can be anything from 20 to 100 tonnes in weight and slopes with its highest point at the doorway. Portal tombs are not and were never covered in a mound but stand with the stones exposed.

There are about 180 portal tombs in Ireland. The majority located in the northern half of the country. The tomb as a straight sided chamber often narrowed at the rear. The entrance is marked by tall portal stones. On top lays a huge single cap stone resting on the portal stones on the front and sloping at the rear where it rests on the backstone. In the majority of cases the tomb entrance faces the east towards the sunrise. This is not always the case though as many tombs face different directions.

Good examples of Portal Tombs include Kilmogue, Co. Kilkenny; Poulnabrone in the Burren, Co Clare; Knockeen, Co. Waterford; Proleek Dolmen, Co. Louth and the largest to be found in Europe Brownshill Dolmen, Co. Carlow.

Around 2000 BC, bronze goods started arriving into Ireland. This was the beginning of the Bronze Age. There was a gradual shift to a new form of society with different customs. This might or might not have been caused by the arrival of the new technology and the whole culture required to mine the copper and refine it. Burial customs changed with the end of large tomb building and the start of smaller stone-lined graves called 'cists'. The Bronze Age people specialised in another type of large stone monument, unconnected with tombs: the stone circle.