When the Celts settled in Ireland they found a lush countryside with much of the land covered in forests, many oak trees, and large areas of bog and marshland. There were also open plains for the people to grow crops and graze their animals. The Celts were an agrarian people; their homes were isolated rather than grouped together. There were many types of dwelling places, such as Hillforts, Ringforts and Crannogs.

Massive ramparts, sometimes two or three in a row, encircled hilltops, with deep ditches around the outside. These hillforts were used for assembly of the tribes when the people were in danger, and it appears, were used for ceremonial functions. Along with being huge structures, a vast view of the countryside could be seen.

Along the coastline the Celts built Promontory Forts, wherever the land extended out into the sea, so the fort was defended on two or three sides by the sea and by defensive ramparts on the land.

Because there are no structures uncovered other than the large communal ones, historians are not able to determine where the ordinary person lived, at this time in history. When Christianity arrived in Ireland many other changes were also taking place, one of which was farming. Individual farmsteads became the norm and by the fifth century many families were living in what are known as Ringforts. These were isolated farms scattered throughout the country. Though called ‘forts’ they were not designed for defense. A Ringforts is a farmstead which consists of an earthen or stone circular bank sometimes with a ditch on the outside, enclosing a house and farm buildings.

The Ringforts varied in size. The surrounding bank of earth or stone would have been quite high and protected with a wooden fence. There was only one entrance to the fort, which would have been closed at night. The dwelling house and storage buildings would have been inside the fort and some of the land outside would have been cultivated. The animals would have been brought inside at night to keep them safe.

The houses within the fort were usually circular, the walls made of wood or wattle and the roof supported on wooden poles and thatched with straw, reeds or rushes. Without separate rooms, bedding would have been spread around the walls. Everything was done in this one room. A Celtic Chieftain would have had a much larger Ringfort; the King’s Ringfort would have been much stronger and greater to accommodate the larger group of people and animals and provide protection from his enemies.

Along with the Ringforts, other people lived in what is known as a Crannog. These were artificial islands made in the middle of lakes or bogs. They were made up of a variety of different materials, usually peat and brushwood plus logs, stones, straw, rushes and animal bones. The Crannogs would then be fenced around with timbers, with additional timbers driven into the foundation to hold the different layers together.

Each Crannog seems to have belonged to individual families, where their farms were on the surrounding shores and currachs (similar to a canoe, skins stretched over a wooden frame) were the chief means of transport.

Different Irish terms were used for the forts; those surrounded by an earthen bank were commonly called rath, dun or lios, while the terms cathair and caiseal were used for those with stonewalls. Townlands throughout Ireland take their names from the local prominent dun or lios, or by whatever name a particular Ringfort was known.

When the Normans’ invaded Ireland in 1169, they were far superior in warfare than the Irish. As they killed and conquered they built┬ácastles primarily as dwellings of military defense. These massive structures also served as a means of intimidation and power over the hostile native Irish. As new building methods had developed, the castles were made of stone, with very thick walls and tall towers, a Keep or stronghold, which was the most secure part of the castle, and where ordinary living took place and a curtained stonewall surrounding the castle. Many were constructed where there were natural defenses, such as on hilltops or by a body of water. These were massive structures that dominated the countryside.

The main entrance, which was the least secure part of the castle, had a drawbridge and machicolation projection over the gate from which missiles could be dropped on the enemy, ie, boiling water, stones etc. The stronghold or ‘Keep’, was the strongest building within the walls, and usually had watchtowers and might have been in the center of the complex. A chapel could have been part of the complex and there would have been small gardens to grow herbs, fruits and vegetables.

There were several types of castles in Ireland, the Motte and Bailey. Usually it was a circular complex that could have had more than one bailey (courtyard), and surrounded by a ditch. The Motte was a very high man-made mound of earth with a keep surrounded by a wooden palisade (fence), where the surrounding terrain could be observed. There was a fly bridge between the two areas that could be dismantled in case of attack. This was a relatively quick and easy type of castle to build and it provided protection.

The Curtained Wall Castle consisted of a keep that was surrounded by a stonewall. There were several watchtowers and other business of the castle was conducted in buildings within the bailey. Since the entrance was still the weakest part of the castle, a gatehouse or barbican was constructed which also had a metal grate. Attacking the enemy at the gate, from above at the towers and on the sides could protect the castle.

There were also Tower Houses that were rectangular structures with the residence, hall, chapel and kitchen. There were one or two floors and had a roof over the entire structure. They were built for the protection of the local chieftain and his retinue. Later the Round Tower was built, with the same purpose, but was a stronger structure in order to withstand an attack.

Some of the castles were built only for military pursuits and administration of the countryside. Usually these types of castles were without a Keep but did have the high curtained walls and massive gate towers, they were still defense structures. Some of these stone castles were built over other fortifications usually made of timber.
The castles were built in Ireland from the 12th century to the end of the 17th century when gunpowder and artillery were introduced. No longer was the castle secure as a strong house. The wealthy landlords, who now owned the castles as a result of the Cromwellian resettlement, (land taken from the Irish and given to English, Scotch and Welsh Planters), and destruction of the Gaelic order, moved from the castles and built more comfortable homes. Many castles and towers are still standing in some form of their original grandeur, but now a ruin. Other castles have been turned over to the National Trust in the Republic of Ireland or to the State Care System in Northern Ireland to be refurbished and opened to the public as National Monuments.

Still other castles have been transferred between families, bought and sold, rebuilt and restored to either a Bed & Breakfast accommodation, Hotel or Self-Catering property, or a National Monument or Heritage Center. It is a testament to the builders of those castles several hundred years ago of their skill and talent, in building structures that are still in existence today.