I have visited this park several times on day trips from expedition ships, in 2019 and early 2020.
Amber Mountain is a national park protecting isolated rainforest located in the extreme north of Madagascar.
Antsiranana Bay is also known as Diego-Suarez Bay. Both names are a mouthful. The latter is the older name and still used. The former is the Malagasy name and easily confused with many other Madagascan locations starting with an A. It is a natural bay that is almost 20 kilometres in length, and is protected from the open Indian ocean winds by a narrow inlet. The coast has a variety of spectacular geology, including layering, basalt columns and uplifted limestone. The large bay is thought to be one of the biggest natural harbors in the Indian Ocean. The main city of the bay is Antsiranana, and although I have only driven through this town, I was impressed by the colorful colonial style architecture, and it looked like a nice place to stay. The port town is used to access Amber Mountain National Park.
The park covers an area of 18,200 hectares on an isolated volcanic massif of mostly basaltic rock. This is one of the most biologically diverse places in all of Madagascar with seventy-five species of birds, twenty-five species of mammals, and fifty-nine species of reptiles. Most of the park is covered in upland rainforest, in contrast to the much drier surrounding habitats. Annual rainfall in the park is 3.5 metres, compared with just 1 metre around the town.
Amber National Park is reasonably accessible, in relative Madagascan terms that is. Bush taxis travel to Joffreville daily from Antsiranana, taking about an hour. There are nice lodges on the road on the way up. Most have chameleons in the gardens. Another had habituated lemurs, and a private reserve with trails and a creek.
There are many trails around the park, and even visits that we did late in the day turned up wildlife. Various mammals, including lemurs, were seen. But the park is probably most rewarding for it's range of Madagascan rainforest reptiles.