Complex sentence: No proper records of the exact dates of establishment of temple exist, though it is beyond dispute that Thirunelli was once an important town and pilgrim center in the middle of inaccessible jungled valley surrounded on four sides by mountains.
Split into simpler sentences: No proper records of the exact dates of establishment of temple exists. Though it is beyond dispute that Thirunelli was once an important town and pilgrim center in the middle of inaccessible jungled valley surrounded on four sides by mountains.