The Close was designed by Herbert Luck North (1871?1941), the foremost Arts and Craft architect of his age in Wales, and constructed between 1923 and 1940, with number 21, named Hillcrest, constructed in c.1935.

Hillcrest is a two-storey house constructed of concrete brick cavity walls covered with roughcast render and painted white, roofed in small slates from Gallt-y-Llan Quarry (NPRN 419098). In style, it is very similar to number 23, Dwyfor (NPRN 411860), albeit larger. The entrance is through the original pointed doorway within a central internal Gothic arch surrounded by a wooden gabled slated canopy positioned centrally in a facade with paired steep gables facing The Close. The rear facade has a central entrance through a narrow, pointed arch flanked by shallow buttresses, above which are narrow small-pane windows flanking a circular window. Casement windows in both front and rear from Henry Hope & Sons. The central chimney between the high peaks of the gables is of red brick with slates sharply peaked over the flues. At the rear of the building is a garage with hipped slate roots and roughcast render walls.

(Sources: Cadw Listed Building Description, Ref No 3548; Richard Haslam, Julian Orbach and Adam Voelchker, Buildings of Wales: Gwynedd (New Haven: Yale University Press, 2009), pp. 438?39)
A.N. Coward, RCAHMW, 25.02.2019