The Bedfordshire Historic Environment Record [HER] contains information on the county’s historic buildings and landscapes and summaries of each entry can now be found online as part of the Heritage Gateway website. Some of the features visible in the landscape around Lower Dean have been tentatively dated, others, like those in Upper Dean have generally been labelled simply as prehistoric due to lack of dating evidence. One series of crop marks which has had to be dated just to prehistory is a block of roughly rectangular enclosures on a ridge top just south of the Three Shire Stone [HER 16624]. The stone marks the boundary between Bedfordshire, Huntingdonshire and Northamptonshire and lies just south of the B645 between Tilbrook [Huntingdonshire] and Hargrave [Northamptonshire]. It is the most northerly point in the county.

In the early years of the 20th century Rev. Boultbee, Vicar of Hargrave is reported as digging into “some Saxon rubbish pits” near Manor Farm, to the east of Lower Dean [HER 8206]. He found pottery, bone and a bronze brooch. These may, perhaps represent finds in Huntingdon Museum identified as Iron Age. Romano-British pottery was said to have been found at Manor Farm at an unspecified date [HER 339].

Lying near Lower Dean to the south-east is a site called Harrowick. It is suggested that this place name has a 5th to 7th century origin as it means "farm near sacred pagan groves” (see the name Harrowden in Eastcotts). This sacred grove may relate to some prehistoric feature in the landscape which made an impression on early Anglo-Saxon settlers [HER 750]. These features may now be represented only by crop marks [HER 2428]. They comprise two parallel strings of complex roughly rectangular enclosures, extending for about one kilometre along a south-west to north-east ridge. The group includes an unusual small double-ditched trapezoidal enclosure.