Comoros

Arrive at Prince Said Ibrahim International outside Moroni, most likely on the overnight from Nairobi, Addis or Dar. The afternoon is the capital, which is small, sun-bleached and immediately likeable: the medina's coral-stone alleys and carved teak doors, the Old Friday Mosque of 1427 standing where the tide reaches the wall, and the Volo Volo market for the vanilla, cloves and dried fish. Sunset from the corniche, and dinner looking at the volcano you will be on in two days.

North around the island. Lac Salé, a brackish crater lake in a perfect cone above the sea; the Trou du Prophète, a sheltered bay where tradition says the Prophet's followers landed; the beaches at Mitsamiouli and Chomoni where the black lava runs into white sand. Between them, an ylang-ylang distillery at work, flowers picked before dawn and steaming in a copper alembic over a wood fire, and the vanilla and clove gardens on the same slopes. Back to Moroni for the CNDRS coelacanth collection in the late afternoon.

The big day on Grande Comore. From the trailhead above Boboni the route climbs through plantation into montane forest, then out onto open heath and finally a black ash plateau, five to six hours of steady walking to the rim at 2,361 metres. The caldera is three kilometres by four, one of the largest active craters anywhere, still steaming from the 2007 eruption. Those who want the sunrise camp on the rim with the porters and the guide; those who would rather not can take the shorter forest walk and the crater lakes below.

The short flight to Mohéli, the smallest, wildest and least developed of the three islands, then across it by road to Nioumachoua on the south coast, where the marine park begins at the beach. The afternoon is deliberately unstructured: an eco-lodge on the sand, the first swim, and the islets sitting offshore in a line. In whale season the blows are visible from the veranda, which tends to end conversation for a while.

A full day on the water in the park with its own guides. From July to October the humpbacks are here to calve and the boat works slowly and at distance, on the park's rules rather than anyone's expectations; mothers and calves regularly surface within metres anyway. Outside that window the day belongs to resident spinner dolphins, the reef around the Nioumachoua islets, and, with luck, the dugongs that still graze the seagrass here. Snorkelling over coral that has never been fished hard, and a beach lunch on an islet.

Inland in the morning to Dziani Boundouni, a sulphurous crater lake in the middle of the island, and a walk in the last stands of Mohéli's forest where Livingstone's fruit bats, among the largest bats in the world with a metre-and-a-half wingspan, roost in the tall trees. In the evening, east to Itsamia, one of the western Indian Ocean's great green turtle rookeries, where the village runs the patrols itself. You walk the sand after dark with the guardians and watch a female haul out, dig and lay.

The flight east to Anjouan, the mountainous and most fertile of the islands. Mutsamudu is the old Shirazi capital and its medina is the densest in the archipelago: narrow lanes of coral rag, carved doors, and the Friday mosque of 1427 at its heart. Above it the citadel of 1860, built against Malagasy raiding, looks over the harbour and out to Mayotte on a clear day. The afternoon walks the old town with a local guide, and the evening is at the waterfront.

A day in the island's interior, which is the greenest country in the Comoros. The road climbs through ylang-ylang and clove plantations into forest below Mount Ntingui, with the Dzialandzé plateau and the waterfall at Tatinga on the way; Bambao has one of the oldest and largest ylang-ylang distilleries in the country, and a colonial-era sugar mill beside it. The afternoon runs the coast road through Sima and Moya, where the beach sits below a cliff and the water is turquoise, and back to Mutsamudu.

The morning flight back to Grande Comore, deliberately scheduled with most of a day in hand because the domestic network here is honest about very little and we would rather hold the margin than lose your connection. Depending on timing there is a last hour in Moroni for the medina and the market, and a final lunch on the corniche, before the transfer to the airport for the evening departures. The Comoros pair naturally with our Madagascar, Seychelles and Mauritius expeditions.