Complex sentence: Ownership has been with the McNamara's or the O'Briens for the past thousand years and the woods at Cratloe hill are the subject of poems and stories going back at least until the 17th century.
Split into simpler sentences: Ownership has been with the McNamara's or the O'Briens for the past thousand years. The woods at Cratloe hill are the subject of poems and stories going back at least until the 17th century.