The exceptional preservation of organic remains in a well-reservoir at the site of La Tabacalera (Asturias, Spain) is the subject of an interdisciplinary study regarding past human-environmental interaction. The feature, dated to Late Antiquity, corresponds to a large well containing a wide range of organic material (animal bones, pollen, non-pollen palynomorphs (NPPs), mites, seeds, wood and wooden artefacts, etc.). This article examines both plant micro (pollen and NPPs) and macro-remains (seeds and wood) dated between the late 5th–8th c. AD. The palynological evidence suggests that the structure investigated was colonised by different species dominated by ivy, while the surrounding anthropised area was characterised by the presence of open areas, probably occupied by meadows and pastures. A mixed deciduous forest was also present not far from the site. The abundant plant macro-remains include the presence of water-loving woody species, which inform us about the vegetation growing around the well-reservoir. The seed record comprises cultivated plants, and a wide range of wild species typical of humid environments. Among the remains there are also some wooden artefacts. Plant remains have provided significant information, not only to reconstruct the landscape around the site, but also on the formation of the feature’s backfill. Moreover, the remains offer us information regarding objects of daily life and the maintenance of the feature.