There are around 3,300 structures that can be classed as hillforts or similar "defended enclosures" within Britain. Most of these are clustered in certain regions: south and south-west England, the west coast of Wales and Scotland, the Welsh marches and the Scottish border hills. British hillforts varied in size, with the majority covering an area of less than 1 ha (3 acres), but with most others ranging from this up to around 12 ha (30 acres) in size. In certain rare cases, they were bigger, with a few examples being over 80 ha (200 acres) in size.