Heamoor saw initial growth in the 19th century due to its proximity to a major crossroads and the need of farms for agricultural labour. The village originally consisted of two areas—the Hea which is the southern part of the village where the main road enters from Penzance and then to the east of this towards St Thomas's Church. The moor occupies the area at the opposite end of the village and could be seen as the poorly drained area now occupied by the playing fields of Mount's Bay Academy and the housing estate nearby. The reason for the moor was the poor drainage which in turn was due to the outcrop of a Felsite dyke (this rock is also called 'elvan' in Cornwall) that can be seen forming the ridge where Poltair woods abuts onto the road leading from Heamoor to Trengwainton. This dyke channels water onto the ground lying below it giving rise to the swampy conditions. Further along the same road are a pair of reservoirs that were once the main supply for the nearby town of Penzance; the water for these reservoirs comes from this dyke. Nowadays the main water supply for the area is Drift Reservoir. The Scout Hut, originally situated in Barn Lane, behind Rosparvah Gardens was the only building to be bombed during WW2. Following the war the Scout Hut was rebuilt in Bolitho Road, behind the British Legion, and named the Venning Hall.