Helodranon' Antongila more commonly called Antongil Bay in English, is the largest bay in Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

. It is at the northern end of the east coast of the island and for administrative purposes it is within Analanjirofo

Analanjirofo

Analanjirofo is a region in northeastern Madagascar. Until 2009 it belonged to Toamasina Province. It borders Sava Region in north, Sofia in west, Alaotra-Mangoro in southwest and Atsinanana in south.Analanjirofo is divided into six districts:...

 Region. The bay is about 60 km long and 30 km wide, and is formed by the Masoala

Masoala National Park

Masoala National Park, in northeast Madagascar, is the largest of the island's protected areas. Most of the park is situated in Sava Region and a part in Analanjirofo. Created in 1997, the park protects 2,300 square kilometres of rainforest and 100 square kilometres of marine parks. The Masoala...

 peninsula on its eastern side. At the northern end of the bay is the island of Nosy Mangabe

Nosy Mangabe

Nosy Mangabe is a small island reserve located in Antongil Bay about 2 km offshore from the town of Maroantsetra in eastern Madagascar. 520ha in size, it is accessible by small boat and is part of the larger Masoala National Park complex. It is a tropical rainforest preserve and sanctuary for...

 and the town of Maroantsetra

Maroantsetra

Maroantsetra is a market town and domestic seaport in Analanjirofo Region, Madagascar. It is located on the Bay of Antongil near .Maroantsetra is the main point of access to Masoala National Park and the Nosy Mangabe special reserve, and the headquarters of the park authority.Access to the town is...

.