A burnt mound is an archaeological feature consisting of a mound of shattered stones and charcoal, normally with an adjacent hearth and trough. The trough could be rock-cut, wood-lined or clay-lined to ensure it was watertight. Radiocarbon dates vary quite widely, the earliest being Late Neolithic, with clusters of dates between 1900 and 1500 BC and 1200–800 BC, with some outliers in the Iron Age. There are also some dates that go into the Early Middle Ages. The technology used at burnt mounds has much greater antiquity and is found from the Palaeolithic onward.

The shattered rock fragments are thought to be the remains of stones heated in fires, which were used to heat water. The shattering of the rock appears to have been the result of thermal shock when the heated stones were dropped into liquid, normally believed to be water.

The mound is assumed to result from the periodic clearing out of the trough, with the stone fragments and charcoal being cast up into a mound. The mound is frequently a crescent shape, which is seen as being the result of the upcast.

There has been considerable debate about the time required to create the mounds. Some interpretations posit the rapid accumulation of material, as a trough was used intensively and very frequently; others suggest a slower accumulation, where the trough was used occasionally over a long period of time. One thesis is that mounds were created at hunting sites; this explanation would most likely result in the latter pattern of accumulation, while the former would suggest that the use of the trough was for an essentially domestic purpose.

The vast majority of burnt mounds are found in the uplands of Great Britain, and in Ireland where they are called fulachtaí fia. Recognised from the nineteenth century onward, they attracted little significant interest until the 1980s. In Ireland they are often found in low-lying ground close to water. In Britain, they appeared to have a distribution pattern confined to the higher ground. However, this may be illusory, as examples have been found at lower altitudes during linear route excavations. The reason that they had not been recognised before was that the mounds have been ploughed out, although the trough may partially survive and there will be layers of the burnt mound material surviving as a spread of material. The mixture of burnt and shattered rock with charcoal, labelled as burnt mound material, is found on occasion without the trough. There are settlement sites on Orkney, where the burnt mound material is found as thick layers , but there is no trough to explain the shattering of the rocks.

The upland bias in distribution in Great Britain has led to a suggestion that they were cooking sites for hunting parties, and there are images from Medieval Irish texts that appear to show this. The burnt mounds are always adjacent to water courses, and there can be several instances along the same burn or stream.

The implication found in many accounts of burnt mounds gives the impression that they are found in Ireland and Scotland, but they also are found in Wales and in England. The Welsh examples tend to be upland and rural, as are many of the English ones, but there are also many found in the lowlying English Midlands.

Burnt mound material has also been found elsewhere in northwestern Europe, such as in Sweden and Switzerland.