GUARDIAN The ceiling fans in Mombasa airport were barely able to paddle in the heat. What air they churned up only served to make the place welter some more, so I was pleased to escape it and travel a couple of hours north up the coast road to Kilifi and spend time in Baumontia House. Perched high on a ridge overlooking an enormous creek, it captured small breezes that came trickling out of nowhere.

The owner was there to greet me. Sheenagh is archetypal old Kenya, part Head Girl and – I imagine – part Party Girl. She apologised for the heat – wholly unnecessary as that’s what I’d come for. Philip, the chef, followed out to pick up my luggage. Amiable and laid-back, he wore the crispest white shorts I’ve ever seen.

Kilifi is a sybarite’s idyll. Bizarrely for Africa, it has a peculiar hint of Hollywood. Baumontia House has the cool understated glamour you might dream of in Cannes, but could never afford because you’re not Elton or Naomi. It’s very seductive. A small group of yachts smacking of millionaires bobbed chicly across the bay; yet the whole point of me being there was to stay in affordable accommodation without getting sucked into the all-inclusive hotel deals that are more widely available. Renting beach houses is relatively cheap; six people sharing will pay from about £20-£30 a night each.

The idea of a self-catering holiday sends a chill through me. It brings back images of dilapidated bungalows on the south coast, musty kitchens without pans, ready meals and rain. But self-catering Kenyan-style is revelatory; it’s an oxymoron really, as there’s nothing “self” about it, other than buying in food. Beach houses in Kenya are staffed with cooks and maids who will do all the work for you – and yes, for a woolly liberal like me it took a little bit of getting used to.

The biggest decision of the day was to name a time for afternoon tea. I plumped for 4.30, then set off to explore the local shops. Kilifi market is pure Africa, humble stalls constructed out of branches and offcuts of wood are covered from the sun with makute thatch or lengths of sacking. Among the kanga sellers, ironmongers and hawkers flogging pastel panties and startlingly large second-hand bras are the grocers. A wide variety of fruit and veg is available for pennies, but if shopping locally puts you off, there’s a supermarket on the main drag. Don’t miss out on the adjacent large indoor market or the fish shop beside it that sells lobster for 900 shillings (about £7) a kilo.

Bang on time, Philip served tea with amazing chocolate brownies that were all chocolate and no brownie, and we discussed what would be on the menu for supper that night, leaving me just enough time for a sundowner.

Kilifi boat yard is a vaguely shambolic affair. Yachts out of water and small wooden warehouses skirt the shoreline, and a small bar with a sandy floor nestles at the far end. It was bereft of customers apart from me and an American guy. He was thoroughly tanned, slightly wild-eyed and had an easily triggered laugh – even though there was nothing to laugh at. Adam had set sail from Thailand a few months previously, but brought his boat in for repairs. He’d been in Kilifi for weeks – all washed-up and a tad deranged. He had little idea of how long he’d be staying, having been caught by the spell of the place. Even so, he looked a little sad and lonely when I left.

The most important fixture in Baumontia House is a large wooden box that might have been knocked together by an African Chippendale (I’m thinking cabinet-maker rather than male stripper). It had the slidey-topped features of a Wall’s ice-cream freezer, except it was crammed full of wine, beer and soda, just my kind of fridge. Philip meanwhile transformed himself, serving dinner in a djellaba; he’d also surpassed himself in the kitchen, feeding me a delicious spinach souffle and prawn curry.

I spent the next morning working on a tan and splashing about in the circular pool. It has a diameter of about 10 feet, so I felt like an aquatic hamster doing my laps. But don’t come to Kilifi for a high-octane holiday; it’s way too laid-back. If your idea of bliss is to eat, drink and chill out with half a dozen mates in inexpensive luxury, then this is the place to do it.

An hour up the coast is Watamu and a house called Watamu Treetops, formerly Lizard Towers. The old name summed up the equatorial eccentricity of the place: I’d like to guess that four people designed this extraordinary tree house: a hippy, Heath Robinson, Gaudí and a local tribesman. Built on stilts on the crest of a ridge, the structure twists around bridges and flying staircases. Blocks of stained glass and mirrored mosaic decorate all the surfaces, creating a colourfully lazy vibe. Lizard Towers is absolutely child-unfriendly – there are way too many opportunities for nasty falls – but it is very adult-friendly, especially so for this one. I loved it.

Kingi, the cook, came to find me after I’d settled in – a fisherman was downstairs. I put in an order for octopus – food just doesn’t get any fresher – before nipping back to the top of the house and my bedroom. It is the first time that I’ve ever wanted to hang out on my bed instead of elsewhere – like a crow’s-nest with open walls, the room commands fabulous views of the beach and surrounding countryside; the word funky doesn’t do it justice.

But I couldn’t stay there all day, and reluctantly dragged myself away from my sanctuary along a path through a small dusty wood that led down to a stunning white coral-sand beach. It appeared to last forever, and there was only one other soul on it. A local guy was splashing around in the water with a grin as big and guileless as the one that had plastered itself on my face.

Ocean Sports is the neighbourhood bar used by wazungu (white folk) and locals alike. Children somersaulted down the beach in front of it, defying gravity with bravura flip-floppery as far as the water’s edge. Lugubrious camels followed them, providing an altogether more exotic take on donkey rides on the beach. A friendly woman called Nicky joined me for a drink as the sky turned Indian pink. She told me about birding in the forest, snorkelling, the local dolphins with a newborn baby the size of a salmon, a butterfly farm and a snake-breeding establishment called Bio-Ken – Barbie’s genetically modified boyfriend immediately sprang to mind.

And then she got on to her passion – marine conservation, turtles in particular. Her enthusiasm was catching. The hatching season lasts from February through to November; and she reckoned that if you stayed a week, the likelihood of seeing one of the beasts was virtually guaranteed. She made me promise to visit LOT (the Local Ocean Trust) the next day to see the community project she had helped to hatch.

Back home that night, Kingi had rustled up a spicy octopus masala stew, which I ate with a bottle of icy-cold white before falling dreamily into bed. I woke early the next day to visit the Gede ruins before the sun got too hot. It’s a bit like entering a lost city: banyan trees and vines drape over dilapidated walls built hundreds of years before by Arab traders. It’s a quiet and beguiling spot that I spent hours in. A matatu (local mini-bus) ran me back into Watamu for 25 pence.

Lamu Heights is a big sprawl of a house that might have come straight out of an ethnic Malibu. David and Daniel were on hand to look after me, or perhaps locate me should I get lost. Its scale was enormous, an average-sized London flat would fit snugly into the kitchen and a family saloon would park comfortably on the ultra-large double beds. Terraces sprang up all over, providing no end of alternatives to the infinity plunge-pool. Open and airy, this was a house that screamed sophisticated party. Lotus-eating wasn’t just expected, it seemed to be a requirement.

The stretch of ocean in front of Lamu Heights is a marine park, so if you’re going to swim kitted out in goggles you’ve got to get a day pass from the Kenyan Wildlife Service, who are situated at the opposite end of the beach from Watamu village. I snorkelled out to a row of buoys some 300m offshore that marked a coral reef. It wasn’t the best place to go looking for coral as it was badly damaged during the last El Niño, but the fish were splendid. I saw a huge Malabar Grouper which swivelled his eyes to look up at me before vanishing contemptuously into the depths.

David had grilled prawns for supper; all I had to do was scoff them . . . until my mobile rang. Nicky was on the other end of the line. A turtle was laying her eggs on the beach; did I want to come along to watch? Dumb question, of course I did – supper would have to be eaten cold.

I had no idea that the female turtle’s sex life was so full-on. They’re right chavettes, copulating with half-a-dozen males. The sperm from them fertilises about 400 eggs, which she’ll lay in up to four nests. The old-lady-of-the-sea that I saw was wonderful: a 70-year-old Greenback over a metre long that had swum thousands of miles back to the place of her birth to start the cycle all over again. She filled up a hole in the sand with a hundred ping-pong sized rheumy moons before carefully covering them and slipping back into the sea. It was a mesmerising sight.

My cold prawn supper and chilled white wine finished off a damn near perfect week of self-catering – Kenyan style.