Complex sentence: Pematangsiantar is an hour away from Toba Lake on the Trans-Sumatran Highway, one of the largest volcanic calderas in the world, and a major tourism destination.
Split into simpler sentences: Pematangsiantar is an hour away from Lake Toba on the Trans-Sumatran Highway. Lake Toba is one of the largest volcanic calderas in the world, and a major tourism destination.