Santa Cruz is the second largest island in the archipelago and the town of Puerto Ayora has the highest population. The giant tortoise reserve is here, as is the Charles Darwin Research Center. It is a dormant volcano, and the twin calderas 'Los Gemelos' are a breathtaking sight. The town center is full of restaurants, gift shops and even a disco! The Red Mangrove lodge here is the best of all the islands and is right on the water with sea lions and marine iguanas often sharing the deck and tables with the guests.