Thornleigh Abbey, commonly referred to as simply Thornleigh, is the residence of Mr Ashcroft and Miss Ashcroft. It is also the temporary residence of their half-brother Richard Ashcroft for the duration of his stay in Darlington.
The estate numerous staff, including Oliver, the footman, and Mrs Nancy, the cook, who is adept at making sweet delicacies. It also has at least two well-trained horses, Atlas and Zephyr. The protagonist visits and dines at Thornleigh on a number of occasions, and it is one of the few places she is able to observe the Ashcroft family at ease.
Thornleigh's exterior grounds appear to be considerably expansive.
The meadows are a flat area suitable for horse riding and wildflower picking.
Includes a path to Rowan's Edge wide enough for horses for travel through. Mr Ashcroft's horses are familiar with this path.
A spectacular view of Thornleigh's grounds can be seen from this point. Mr Ashcroft mentions to the protagonist that this place is his haven from being the carer of his two strong-willed siblings.