Iguanas laze in the airport garden. Finches flit about the departure lounge. Sea lions make a noisy welcome party at the boat pier where sharks lurk in the shallows and blue-footed boobies show off their diving prowess, hitting the water at 60mph. It’s the greatest show on earth – and I’ve only just landed on Baltra Island, the gateway to the remote Galapagos Islands, 600 miles off mainland Ecuador, in South America. It has taken three days and three flights to get here, including a 14-hour haul from Amsterdam and a two-night stay in Ecuador’s capital, Quito, to acclimatise to the altitude of 2,850 metres, before a two-hour onward flight over the Andes. Yes, getting to the Galapagos, in the Pacific Ocean, demands a huge investment in time, effort and money – but for nature lovers it is the most unusual wildlife-watching destination in the world. All creatures great and small are ever-present and fearless of humans because the islands were isolated for so long. Even more thrilling is that much of the wildlife is not found anywhere else in the world. To preserve this unique environment, tourism is strictly controlled by the Galapagos National Park Directorate, which issues licences only to a handful of expedition ships. I am joining Hurtigruten Expedition’s 90-guest MS Santa Cruz II for a voyage around the eastern islands. Naturalist Charles Darwin reached here on HMS Beagle almost 188 years ago. He stayed five weeks and his observations were the inspiration for his theory of evolution by natural selection – its plants, birds and reptiles had developed in isolation and displayed varying characteristics on different islands. We make two or three zodiac boat landings a day and each stop introduces a different volcanic landscape and endemic species. From a sunset walk along Mosquera Islet, an idyllic white sandbar littered with sea lions and Sally Lightfoot crabs, to North Seymour, an eerie landscape of white-bark incense trees where frigate birds nest and marine iguanas pile themselves high to keep warm, every island is a soul-stirring discovery. MS Santa Cruz II’s guests – mainly retired over-60s from the UK, Germany, Netherlands, US and Canada – bond easily, looking out for each other on tricky terrain and sharing the joy of mockingbirds hopping around our feet, sea lions swimming around the ship and tropicbirds gliding above our heads. Sadly, we humans do not always deserve the animals’ trust, as I find out on my first snorkelling tour when a cheeky young sea lion, blowing bubbles in my face and looping the loop, wins my attention as I swim with a school of yellowtail surgeonfish.