About 25 km south of Puerto Princesa, the Iwahig Penal Colony is one of the more unusual public sights in the Philippines: a working prison farm where inmates with low security ratings live in barracks scattered across an enormous coconut plantation, with no perimeter fence. The administration has long welcomed tourists, and visitors can wander the central area, watch a short dance show performed by inmates, and buy crafts (woven baskets, wooden carvings) from a souvenir shop run by the cooperative.
It is genuinely interesting and not at all sensationalised. Tricycles from Puerto Princesa take about 45 minutes; bring small bills for the crafts.