On September 17, 1835, a 26-year-old Charles Darwin first set foot on the islands that would change not just his life but would revolutionise the foundations of both science and religion as the world knew them. Darwin discovered much more than the process of natural selection -- he has also led us to the closest thing to heaven on earth.

Travelling to this remote archipelago in the Pacific Ocean 174 years later, you arrive at the land that time appears to have forgotten. Our vessel, the Eclipse, is thankfully much more comfortable than the small survey ship, the HMS Beagle, that Darwin sailed on. But the evolutionary connection remains paramount, as this trip is led by Darwin's great-great grandson Randal Keynes to celebrate the 150th anniversary of the publication of The Origin of the Species next Tuesday.

Our voyage begins when we moor beside the soft, white sand of Las Bachas beach on Santa Cruz, where we admire blue-footed boobies, an endemic bird that has the most iridescent cobalt feet. Scowling marine iguanas piled into pyramids soak up the sun on the blackest lava rocks. Ruby-red Sally lightfoot crabs scuttle around them. Then we take a short stroll inland to a small brackish lagoon that is home to several types of indigenous herons. A brazen, young flamingo ambles right up to me until it stands posing less than a metre from my face.

Back on board, our feet are diligently hosed down to ensure we don't transfer any sand particles from one island to the next, as each has its own unique mini eco- system. One of the key rules on this trip is that we don't bring anything with us ashore and the only things we leave behind are our footsteps in the sand to be washed away by the next big wave.

We sail through the night and wake every morning to a new vista, putting down anchor next to a different island. Day two sees us wandering around Santiago Island, with its rugged coastline of archaic lava. Here we get up close and very personal with sea lions who bark as if they need throat lozenges, their babies sounding remarkably like ET. Hundreds more of the wonderfully supercilious marine iguanas glare imperiously at us, baby fur seals curl up in natural lava arches and the air is filled with various herons, hummingbirds, bold mockingbirds and, of course, finches.

This is also our first chance to experience life beneath the waves and the underwater world here is as important as the one above it. My advice is to take every opportunity to dive right in -- snorkelling, kayaking or riding in a panga (motorised dinghy) to witness the hidden treasures that dwell in every nook and cranny.

My opening snorkel sees me in wonderfully crystal clear waters, joined by shoals of the most rainbow-coloured of fish, a couple of huge mantra rays and a group of about 10 welcoming turtles, most of them almost as big as me. They gracefully glide right up to me, regularly causing me to laugh with the sheer joy of it all -- which isn't to be recommended when you're trying to breathe through a snorkel.

The afternoon is spent in a panga motoring slowly around the landmark Pinnacle Rock, admiring blue-footed boobies diving in to catch fish, yawning pelicans and a quintet of playful Galapagean penguins, who are so happily immersed in their games that they don't seem to notice us drifting right alongside them.

Evenings are spent listening to Keynes bringing Darwin's voyage to colourful life, as he intersperses the historical information with the most animated personal anecdotes. We really are following in the footsteps of history.

Interestingly enough, the very first resident on these islands was actually an Irishman, Patrick Watkins. He became marooned on the island of Santa Maria in 1807 and spent the following two years happily living there, growing vegetables both for his own survival but mainly to trade with passing boats in exchange for rum. Clearly, he had green fingers as the story goes that he managed to remain drunk for most of his stay until he stole a boat, complete with five slaves. No one is quite sure what happened to his crew, though, as Watkins arrived alone at the mainland a week later.

The next morning, we visit Cerro Dragon (Dragon's Hill) on Santa Cruz Island, which was named after the huge land iguanas that patrol this remarkably red and dusty land. Our mission here is twofold: to track some of these dragons and to follow Darwin's lead by identifying as many as possible of the eight different species of finches that live here. This is not as easy as it might seem, as finches differ primarily just in the size and shape of their beaks, which all look rather similar to this novice. But, apparently, we do witness six types. Thankfully, land iguanas are much easier to spot as, unlike their marine cousins, they are the brightest golden yellow and appear to smile rather than scowl.

This is just one of many moments when I wonder if I've wandered onto the set of Jurassic Park. At other times, I feel like I've strayed into the deepest jungles or landed on the moon, such is the otherworldly nature of the landscape. And this weird and wonderful world is inhabited by the most glorious creations that are beyond imagination.

Each day is crammed with so many new sights, sounds and emotions that it feels like a week. Even a short panga ride to shore is enlivened by passing turtles, sting rays, penguins, sea lions and various types of sharks.

On Espanola Island, we walk up a rocky path from a cove filled with mountains of marine iguanas, Sally lightfoot crabs and some very chatty newborn sea lions. Our progress is interrupted by the discovery on the path of two booby nests and a male blue-footed booby minding two young ones, with their twisted dark faces surrounded by the most brilliantly white fluff that resembles cotton wool.

A few steps further and we find ourselves beside a bizarre lunar-esque field that is soon revealed to be a landing strip for albatrosses. Looking up to admire these giant birds descending, we almost step on some of their rather huge offspring. With their mottled khaki-coloured fluff, these big chicks are brilliantly camouflaged by the dry leaves that surround them.

We reluctantly move on to the island's cliff edge, but here are rewarded with albatross takeoffs as they leap off the rock face at speed. And beside us is the island's famous blowhole, which obligingly performs with giant 40ft jets bursting through and refreshing us with the clouds of spray.

Returning from this display, we witness four adult albatrosses performing like expert fencers as they engage in their famous mating dance ritual, all against the dramatic backdrop of a blushing sky as the red sun sets.

There are three naturalists accompanying the cruise and the passengers break up into small groups of about six, depending on what activity we choose. Armed with impressive local knowledge, the naturalists are also all remarkably sharp-sighted, spotting turtles' heads almost before they've broken the surface of the water, and differentiating between the multitude of finches with an enviable ease. They transform a secret landscape into a vibrantly alive one.

At the Charles Darwin Research Station on Santa Cruz, we meet the infamous Lonesome George, a giant tortoise reckoned to be well over 100 years old who is thought to be the last of his species. The good news is that George isn't so lonely anymore as he has two female companions who are a very close match to him. Eggs have been laid and there are many fingers crossed that they will safely hatch after a previous batch was sterile.

We travel up into the unexpectedly lush highlands to visit a cattle farm that has been somewhat overtaken by saddleback tortoises wandering its fields. I find one particularly huge one sheltering from the harsh sun in some long grass and proceed to have a prolonged conversation, until he gets particularly inquisitive and slowly ponders up to smell my face. He then continues to plod past me, obliviously knocking me over with his enormous shell as he goes, before looking back at me as if to see if I am coming with him.

On Fernandino Island, flightless cormorants furiously beat their stumpy wings in order to dry them before diving back into the sea to catch their fish suppers. And this is all under the watchful eye of huge frigate birds, who can't swim but instead survive by stealing the catch of other birds.

But my most unforgettable memories are carved when I am below the waves. On one particular swim, I turn a corner and am in true turtle cover, with 30 or 40 of these magnificent beasts gliding right underneath me, so close that I am actually carried on one of their shell homes. A flightless cormorant momentarily disturbs my revelry by diving in right beside me, followed by two bullet-like penguins.

And, on my final snorkel, I find myself in an underwater playground for adolescent sea lions. They dive straight at my face as I swim as fast as I can at them and then, just before we crash, they blow bubbles into my face as if they are laughing.

I don't think I have ever felt so alive.

- Sophie Gorman

Irish Independent