Complex sentence: In a field near the church may be seen the outline of an extensive quadrangle; and, when Hutchinson wrote, there where, what he conceived, indications of a large edifice having occupied the spot.
Split into simpler sentences: In a field near the church it may be seen that an outline of an extensive quadrangle used to exist. When Hutchinson wrote, there where, what he was conceived by, indications of a large object having occupied the spot.