Excavations of 1905-1907 found Neolithic flint tools and evidence of an earlier Iron Age enclosure beneath the principle settlement. CP3203/20/1 and 2 may be of this earlier occupation phase.
CP3203/20/1 shows some very scattered stones; CP3203/20/2 shows the remains of a round stone hut.
From Bezant Lowe's Heart of Northern Wales Vol. 1 (1912) Pages 117-118.