Ponnumthuruthu island is also known as Golden island and is one of the most beautiful uninhabited islands in the state of Kerala. This offbeat spot is caressed by the Anjengo backwaters and lies about 20 km from Varkala. This island has a five-acre radius and can be accessed only by a jetty from the Nedunganda village.

The island is a hub of migratory birds as it is kissed by the serene waters of the Akathumuri Lake. It also holds significance among spiritual travellers, who sail here to see a popular 100-year-old Shiva-Parvathi temple. It is locally recognised as 'Thuruthu Kshethram' and both the island and the temple are owned by the Valiyapurackal family. The festival of Mahashivratri, dedicated to Lord Shiva, is celebrated with great pomp and show and devotees flock in great numbers to attend the event.