Legends of Langkawi
Tasik Dayang Bunting
Tasik Dayang Bunting is a fresh water lake on the island of Dayang Bunting, the second largest in the Langkawi archipelago. There appears to be several versions of the Dayang Bunting legend.

One version has it that Dayang Bunting was a giant guardian spirit that kept watch over the islands. The lady's defenses include her pet lion and poison from the tuba root, potent weapons for her protection. Hence, the two islands closest to Pulau Dayang Bunting, whose silhoutte resembles that of a reclined pregnant giant, are named Pulau Singa Besar (Great Lion Island) and Pulau Tuba (Poisonous Root Island). The story goes that, a group of rude merchants failed to pay the obligatory respects to Dayang Bunting as they passed by the islands. Rudely awakened by the intrusion, she summoned her pet lion to despatch the trespassers. She roused the spirits of wind and water, stirring up a tropical storm that unleashed its fury on the incoming fleet of sailors.
The howling winds and tossing waves threw and dashed vessels on Pulau Jong (Junk Island), hence the remains of wrecked vessels. In the stormy affair, a cargo of black and white water buffaloes escaped to Pulau Gubang Darat (Land Stable Island) and Pulau Gubang Laut (Sea Stable Island) while the white buffaloes sheltered at Pulau Balar (White Water Buffalo Island). Yet other boats, laden with rice, was stranded at Pulau Beras Basah (Wet Rice Island).

In another story, a prince once ate half cooked rice during a wedding feast. He suffered indigestion and farted at two spots now known as Pulau Kentut Besar (big Fart Island) and Pulau Kentut Kecil (Small Fart Island)!

The second version of Dayang Bunting is closely associated with the romantic exploitery of Mambang Sari, a beautiful female genie and Mat Teja, a male genie. Mambang Sari used to frequent the island accompanied by her maids. Their favourite spot was Pasir Teluk Air Tahun and Teluk Lawak. One day Mat Teja saw Mambang Sari and was struck by her beauty. He fell in love with her and used to follow her wherever she went. Once while on a lookout for her, he met Tok Diang an old man from the village. Mat Teja told him of his love for Mambang Sari but just did not know how to reveal this secret. He feared that his love might not be reciprocated.
Tok Diang asked Mat Teja to get the tears of a mermaid from the sea and to wipe them on his face the next time he met Mambang Sari. He did just that and when Mambang Sari saw him she fell in love with him. They often met at various places to enjoy the beauty and serenity of these spots. They became more intimate and as a result Mambang Sari became pregnant.
She chose to retire at Tasik Dayang Beranak (Lake of Born Maiden) to give birth. Unfortunately the child died after seven days. Saddened by the death Mambang Sari took the child's body and threw it into the lake, Tasik Dayang Beranak. The lake later came to be known as Tasik Dayang Bunting. Some people believe the water of the lake possesses some mystical power of helping barren women to bear children.

from here