Mount Karthala

Mount Karthala, the great active volcano that rises to over 2,300 metres and forms much of the main Comorian island of Grande Comore, is the archipelago's most dramatic natural feature and possesses one of the largest active volcanic craters in the world. A challenging two-day trek climbs through zones of forest, heath and bare lava fields to the vast, desolate summit caldera, a stark, otherworldly moonscape of ash and rock, sometimes venting steam and scarred by recent eruptions. Camping near the rim and witnessing sunrise over the immense crater and the ocean far below is a genuinely unforgettable adventure for the fit and intrepid.

What you actually see

• The summit caldera - one of the world's largest active craters.
• The trek - the two-day climb through forest and lava.
• The lava fields - the stark volcanic moonscape near the summit.
• The sunrise - the dawn over the crater and ocean.

When to go

May to October, the cooler, drier season, for the best trekking conditions, as the wet season brings heavy rain and mist; the climb is a demanding two-day trek best done with a local guide, camping near the summit. Note that Karthala is genuinely active, so eruptions can affect access, and conditions should be checked.

Honest expectations

The climb is a serious, strenuous two-day trek on an active volcano, requiring good fitness, a guide, and camping gear, with basic conditions and the risk of mist, cold and rain hiding the views; Karthala's activity can also restrict access. For the fit and adventurous, though, summiting one of the world's greatest volcanic craters is an extraordinary experience.

Nearby

The capital Moroni and the coast of Grande Comore are within reach.