For a time , Capel Lligwy was used as a private place of worship for Lligwy House , a " venerable mansion " once owned by the Lloyd family which came into the possession of William Irby , 1st Baron Boston , in the 18th century . After the early part of the 18th century , however , the chapel became unused and began to fall into disrepair . The walls remain to gable level , with some traces of render on the inside , but the roof has gone .