Malangwa is a town, a municipality, and the headquarter of Sarlahi District in Madhesh Province of Nepal. The district's oldest municipality is in …Malangwa is a town, a municipality, and the headquarter of Sarlahi District in Madhesh Province of Nepal. The district's oldest municipality is in Parliamentary Constituency 2. From the Mahendra Highway 25 kilometres south of Nawalpur, a small highway-side town. Situated at an altitude of 79 meters above sea level, Malangwa is near the Indian border at Sonbarsa. There is a customs checkpoint at the border crossing.