Siwalan is a type of palm trees that grow in many coastal regions in hot and dry area with the sea breeze is blowing a little stronger. Tuban Regency and some areas along the north coast (Pantura) of Java, is the endemic place from Siwalan tree.
One of the products from this fruit is Legen, which the water of the fruit. It sweet and fresh and can be fermented into tradition liquor called tuak. While the fruit of siwalan is having sweet and chewy texture like jelly.