Legend has it that Pulau Kukup was once an abode to five celestial princesses. One of the princesses fell in love and eloped with a sailor and evoked a curse upon the whole island.  It was submerged by the sea waters only to resurface later swathed in mangroves. Many have tried to settle on this island, but without success. Some say this is because the island is inhabited by spirits.

Rich in biodiversity, it is home to numerous mangrove, aquatic and bird species including protected wildlife groups such as the long-tailed macaque, dusky leaf monkey, smooth otter and wild boars.

This unique mangrove habitat, which is one of the largest uninhabited mangroves in the world was given global recognition as a 'Wetland of International Importance' (Ramsar site) by the Geneva-based Ramsar Convention Bureau in 2003. It was designated a National Park on March 27, 1997 and comes under the protection of the Johor State Park Corporation Enactment 1989.