The new union workhouse was built in 1839 to house 150 inmates.

Its position just outside Llanfaes meant that middle class families would not have to have daily contact with the poor.

Soon after 1834 a model plan for workhouses was issued. Many were built along these lines and they were typically a two storey block forming a cross shape with high walls forming a square.

On the ground floor there might have been workrooms, washrooms, the kitchen and rooms where new arrivals were stripped and cleansed. On the first floor were the dormitories, the staff quarters, the dining hall and rooms for the sick and infirm.