This steep-sided, roughly circular mound rises approximately 10.7 metres high, with a base measuring about 25 metres across and a summit platform spanning 12 metres. The OS 25-inch map marks it clearly, and its distinctive profile suggests it's no natural formation. The upper 3 to 4 metres appear to have been deliberately heightened, whilst the northern side shows evidence of later gravel quarrying that has eaten into the original structure.

Between 1901 and 1906, architect Basil Stallybrass documented the site with detailed section drawings that revealed the deliberate scarping of the hill's sides, confirming suspicions that this was indeed a motte; a type of fortification favoured by the Anglo-Normans. His notes describe an uneven summit with a sloping platform on the western side, about 6 to 7 metres wide and sitting 1.5 metres lower than the main summit. Curiously, he observed no evidence of a bailey, the enclosed courtyard that typically accompanied such defensive structures.

Perhaps most intriguing are the large stones and blocks found in the surrounding field wall, still bearing traces of mortar that hint at something grander than a simple earthen mound. These remnants suggest that Close Hill once supported a substantial masonry structure, possibly an Anglo-Norman castle that would have commanded views across the surrounding countryside. Whether this was a timber fortress later rebuilt in stone, or always a stone castle from its inception, remains one of the many questions this atmospheric site poses to visitors and archaeologists alike.