Bryn Eirin is a two-storey T-plan house constructed over a semi-basement with a slightly lower range to the rear. It is built from snecked rubblestone with slate hanging to the left return and rear wing. It also has a hipped slate roof with two rendered stacks to the rear roof slope and another to the rear wing, the former with decorative chimney pots. It has a two-storey, three-window front with twelve-paned glazing bar sashes. Those to the first floor have slate lintels, whilst those to the ground floor have stone lintels. All the windows have slate cills. There is also a central C19 shallow gabled open porch with timber lattice work and a slate slab roof over a four-panel door.

It is listed as a well-preserved house of c1860, which is a good example of an urban villa built as part of the development of Llanberis as a small mountain resort and urban/industrial centre during the C19.

Source:- Cadw listed buildings, NJR 27/11/2008