ENLithuania is called a land of hillforts. At present about 1,000 hillforts are known within the Republic (an area of 65,200 km2). Sixty per cent of these are late hillforts used at the beginning of the 11th and up to the 15th centuries. These are the sites of former wooden castles. Not all of them were used at the same time. In different regions their function varies. Many aspects of their existence are not clear at present, but for some of them we have a good deal of data.