Krem Puri in Meghalaya is the world's longest sandstone cave. But that's not the only unique feature of the caves near the hamlet of Laitsohum in the East Khasi Hills district. The 24.5 km-long Krem Puri Cave is also the 'Bhool Bhulaiyya' of the North East, with its intricate network of passageways and corridors that can be difficult to navigate.