The Aldabra is the second largest coral atoll in the world. The Miraculous Territory Aldabra is a place of miracles, a world cultural heritage, a miracle. Aldabra Group, a UNESCO World Heritage Site in the Seychelles. Seychelles travel tips for your holiday. The second largest coral atoll in the world, Aldabra is located in the Aldabra archipelago in the Indian Ocean, which belongs to the Seychelles.