It was a grand old growth and still alive and carefully looked after.
But the younger trees in the pic below are closer to home and were only planted at the start of the railway era (1830s). They are on a wide bridge over the old railway path from Bishop Auckland to Durham...now known as the Auckland Way and turned into a footpath and bike path.
The Bishop of the time didn't want to see the smoke or soot of the trains and ordered a bridge to be built, wide and deep enough to grow trees to hide the track below. These trees are still growing.
Further into Auckland Park, which the Bishop's carriage would cross on his way to his palace at Bishop Auckland, were ancient meadows for grazing and trees which sheltered the deer. These strange lumps on the old meadows are the remains of ancient ant hills.