The cottage named Pentre, in the Nant Ffrancon valley area in Snowdonia, was the first the Piper family rented in North Wales. They renovated and rented the cottage for a year, staying there repeatedly until the autumn of 1946.

During this period, Piper became fascinated with the rock formations and dramatic landscapes in the area, recording them in considerable detail. In his notes he described the specific colours of different areas of rock that he observed across various weathers and times of day. He also studied the walls that he found in the area, noting their methods of construction and the types of stone used. Many of Piper’s best drawings and paintings of Snowdonia were never seen in Britain as he dispatched a whole exhibition (which included Wall at Pentre) to New York’s Buchholz Gallery. The work is accompanied by an original copy of this exhibition catalogue and bill of sale from the Goldmark Gallery, 2015.