Text: They measure 2 1.2 km (1 1.2 miles) long, averaging 12 meters (40 feet) in height, with 88 towers and an estimated 2,500 niches suitable for sentries or marksmen.
Entailment: Averaging 12 meters (40 feet) in height, with 88 towers, they measure 2 1.2km.
Contradiction: They have an estimated 5,000 niches suitable for sentries or marksmen.