Alltwen is an earlier C19 Llanerchaeron estate cottage. It is roughcast with a slate veranda roof and roughcast end stacks, which are large and square to the left. It is a single-storey building with a two-window front recessed under an overhanging roof carried on three plain thin iron posts. The windows are Gothic in style, being pointed with intersecting tracery to the heads and six-pane lights below. There ia also a door on the left end wall.

It is listed as a well-preserved earlier C19 picturesque estate cottage.

Source:- Cadw listed buildings, NJR 09/12/2008