The first record of human presence in Sussex dates back more than half a million years. Not surprisingly, there is very little archaeological evidence from this Paleolithic period but a great deal has survived from the later Mesolithic period that began some 14,000 years ago.
Selmeston lies between two rivers, the Cuckmere and the Ouse and the line of the village, the present day Street, is the watershed between them. Early humans would have taken advantage of the rivers and there is evidence that they did so. Usually villages were formed on ‘through routes’ from one central location to another.
It is a spring line village, which means that it contains a series of natural springs that provide drinking water. These springs are the result of Selmeston’s proximity to the South Downs, a huge block of porous chalk, and they are fed primarily by winter rain. Nearly every house built in the village before the 1960s has some form of well close by and it was only in the mid 1950s that running water was laid on to each property.
Selmeston has been a favoured site for settlement since Mesolithic times. Early humans would have been attracted to this area because of its natural geographical features and the natural springs fed from the South Downs.
The earliest archaeological evidence we have of some sort of settlement in Selmeston dates from the Mesolithic or Middle Stone Age (12,000-4,000 BC). The people at this time were ‘hunter gatherers’ and as such would have been seasonal visitors.
A survey undertaken in 1933 revealed evidence of their presence in the area of the old sandpits, located close to the Church. Pit dwellings and the remains of a cooking hearth were found, along with over 130 microliths (slithers of flint ) probably used for arrow heads, spear tips and axes in the hunt for wild deer and oxen in the Wealden forests.
Intermittent settlement appears to have continued throughout the Mesolithic period, which gradually ended with the beginning of farming some 6,000 years ago. According to Cecil Curwen  in The Archaeology of Sussex, the sandpit near Selmeston Church is ‘perhaps the most important and instructive of all the Mesolithic sites in Sussex, for here were found some of the dwelling pits of Mesolithic man’. Excavations of these pits in 1933  yielded over 6,400 flints, including a large number of ‘pot boilers’. These are stones which were made red hot and dropped into water to heat it, or used for cooking food. It seems that the pit went out of use and was almost filled with drifting sand, when it was reoccupied by some Neolithic people, who left behind a few scraps of pottery of the kind known as Peterborough ware or Neolthic ‘B.
Various items of pottery dating from the Neolithic (New Stone Age) and Bronze and Iron Ages have been found, some of which are on display at the Barbican House Museum in Lewes.
 The Archaeology of Sussex, by E. Cecil Curwen (Methuen & Co Ltd 1937)
 The Antiquaries Journal April 1934 (Vol. XIV, No.2) – A Late Mesolithic Site at Selmeston, Sussex, by J.G.D. Clark MA, PhD, FSA
 Sussex Archaeological Collections (Vol. LXXIX) – Late Bronze Age Ditches at Selmeston, by Eliot Curwen, FSA and E. Cecil Curwen, FSA
See also: The Antiquaries Journal October 1934 (Vol. XIV, No.4) – A Flint Sickle-flake from Selmeston, Sussex, by Eliot Curwen, FSA and E. Cecil Curwen, FSA Sussex Archaeological Collections 123 (1985) – Recent Archaeological Research at Selmeston, East Susssex, by David Ruling et al.