Chek Jawa is an intertidal flat on Pulau Ubin, an island just off Changi Point. It is the largest natural intertidal flat in northern Singapore and is located on the eastern tip of Pulau Ubin. Previously a virtual unknown, Chek Jawa came into national prominence and focus in the early 2000s when the area's rich biodiversity was discovered almost by chance during a nature outing at low tide.

News on the impending land reclamation works planned by the government on the area sparked a rare show of public-led and coordinated effort to reverse the reclamation plans. The Singapore Government acceded to these requests in December 2001. The biodiversity of Chek Jawa covers different ecosystems such as coastal forests, mangroves, coral rubbles etc. 

Mangrove can be found in the central part of Pulau Ubin along the major water way. While much has been reclaimed as aqua-cultural pond in the past, they have been rehabilitated recently as primary industry declined in recent years. Mangrove is a fragile yet important eco-system and plays a huge part in protecting inland systems, filtering pollution and functions as a carbon sink.