Foz do Iguaçu, Brazil

As incongruous welcomes go, a dodgy waxwork of Will Smith welcoming visitors to one of the Seven Wonders of the Natural World must score quite highly. But his effigy graces the arrivals hall of Foz do Iguaçu airport, at which we arrive having flown over large tracts of rainforest and the huge snaking Iguaçu river before rolling green pastures appear as we come into land. "Sure, it looks like Ireland," proclaims Coman looking out of the window - although the tropical heat and steamy humidity that greets us on the tarmac is about as far removed from Roscommon as you can get.

Our scheduled guide doesn't arrive to pick us up so we take a taxi to our destination. We're staying at the only hotel located inside the Iguaçu National Park but taxis are forbidden from entering so we are rather ignominiously dropped at the park entrance, unloading our bags on the side of the road.

Fortunately a young man in a smart uniform appears, announces himself as Gabriel from the hotel - which has its very own private entrance - and whisks us into a shuttle that carries us 15 minutes to a fabulous, grand colonial pink palace bearing the name Hotel das Cataratas, directly opposite a set of spectacular waterfalls. The word 'cataratas', now commonly meaning waterfall, comes from the old indigenous belief that rocks - as part of nature - could see, and so the waterfalls covering them were like cataracts, obscuring their vision.

After a much-needed lunch we go for a quick wander down to the viewing trail to marvel at the falls, taking care not to get too close to the raccoon-like quatis who scurry around supposedly carrying rabies, before chilling out by the rather splendid hotel pool, readying ourselves for tomorrow's trip across the border to explore the Argentinian side of the falls.

Our guide Christian is full of apologies for yesterday's mix up at the airport but more than makes up for it today by being a thoroughly amiable and knowledgeable companion. He arrives at 8am and drives us across the bridge that spans the Iguaçu river and forms the border with Argentina.

We stop on the bridge at the section where the two countries join, demarcated by a change from the yellow and green road markings of Brazil to the white and blue of Argentina, and look out to the spot where the Rio Iguaçu meets the Rio Paranha, beyond which lies Paraguay - one of the only points in the world where three countries meet.

Once across the Argentine border it's a short drive to Parque Nacional du Iguazu, where we switch from Portugese to Spanish for the day. We start the exploration on foot, with a 2km walk to the park's train station which then ferries us 15 minutes deep into the park to one of the most spectacular experiences we've ever had.

Disembarking, we walk along zinc platforms far out over the fast-flowing waters to the Devil's Throat falls. The roar of the water - 48 million litres a second - and the plumes of spray that rise up in billowing clouds is really quite something to behold and explains Eleanor Roosevelt's simple sigh of "Poor Niagara", when she visited Iguazu. Compared to the majesty before us Niagara is like a leaky tap!

As we venture around the park we are perpetually surrounded by butterflies in vast profusions. Over 200 species of them can be found, along with all sorts of tropical birds, mammals and reptiles. The butterflies regularly land on us, attracted by the minerals in our sweat, and by God do we sweat. The weather is amazing and Christian proclaims it "the perfect day" for us to be visiting.

After almost three hours of trekking through stunning scenery, taking in many of the more than 270 waterfalls in the area, we descend down to the river's edge for a very welcome chance to cool off. Our valuables secured in rubber bags and life-jackets fastened around our chests, we board a speedboat and race into the heart of the falls, bouncing upon the swirling waters and getting thoroughly drenched from the cascading magnificence of the pounding waters. It's the most exhilarating shower of our lives, and screaming with delight we get perilously close to the falling torrent, almost as though we can reach out and touch it.

Our boat trip ends by negotiating the white-water rapids until we dock safely further downstream, soaking wet but grinning from ear to ear. A truck meets us to transport us back through the jungle on a mini safari expedition to rendezvous with Christian, who returns us to our hotel having had one of the most incredible days out in all our travels. It genuinely is one of the Wonders of the World.

Fortunately our hotel is also pretty damn spectacular and we spend a very pleasant afternoon by the pool followed by a quite incredible sunset over the falls. It's one of the benefits of staying at the Hotel das Cataratas that guests have 24 hour access to the park, meaning we can enjoy the sunsets and early morning walks unavailable to other visitors.

We take full advantage the next day, hiking along the Brazilian side of the falls before breakfast, all the way to Devil's Throat with barely another person to be seen. Standing on the platform at the base of the falls with rainbows above us, getting soaked in perfect solitude is a huge privilege and one we will remember for years to come.

We'll also remember the food. Whilst our first night's dinner at the buffet restaurant is nice but nothing special - populated by lots of super-size guests whose only exercise today is their repeated visits to the chiaroscuro station to load up on more dead animals than an industrial abattoir, and featuring a wine list that seems to have tripled the price of each bottle - our second dinner at Hotel des Cataratas is very special.

We are seated under the stars on the verandah of their á la carte Itapia restaurant, run by a celebrated Brazilian chef who serves national specialties. To the sound of cicadas and the distant roar of the falls we are served scallops in a piranha broth and a cold cantaloupe melon and Brazilian champagne velouté followed by Amazonian Piracuru fish and baked salmon. It's absolutely astounding.

The next day, before we leave, we visit the nearby bird sanctuary Parque des Aves which rears and rehabilitates local wildlife along with birds from other tropical regions. Whilst a champion of conservation it is a little sad to see such magnificent birds kept in aviaries, even though some of them are quite vast in scale. The squawking of the parrots is also quite deafening at times so we return to the tranquil environs of our beautiful hotel for the last few hours of our Brazilian adventure.

An overnight stop in a São Paulo airport hotel awaits before our long flight home but one thing we do know is that we'll be back to Brazil. We really have fallen in love with this beautiful country... and there's so much more to see!