I never intended to go to Ol Pejeta, let alone stay. A late night in Nairobi became a slow start the next morning, and the ambition of driving as far as Samburu National Park drifted out of reach. The road north took us as far as Nanyuki, one of the final staging posts before modern Kenya disappears and its northern wilderness takes over. A sign on the outskirts of town retrieved a half-remembered recommendation to look in on Ol Pejeta – a game reserve famous for its work in rhino conservation.

As we entered the 24,000-acre park, a cast of African mega-fauna wandered in the fading light and we lost track of the camp's signposts, eventually trundling up to a deserted lodge. A modern farmhouse mercifully free of the usual colonial shtick thought to be favoured by safari tourists, its huge entrance was lit by a wall of dark wood and glass. Going inside felt like an exercise in shrinking. Enormous armchairs lined the hallway, tall as basketball players and deep enough to shelter a family.

Vast rooms opened beyond wooden portals, each seeming larger than the one before – none more so than the main sitting-room, where a fireplace of epic proportions was stacked with logs the size of harvestable trees. Nothing in the house's use of space made any sense in hotel terms. The impression of having stepped into another world was augmented by the apparent absence of people. We roamed the reception-rooms and got our first clue about our unusual find from the key fob of the upstairs bedroom. Printed in neat letters, it showed the name of one Mrs Khashoggi.

Surely that couldn't be one of the wives of Adnan Khashoggi – the arms dealer who once boasted of being the richest man in the world and in the 1980s appeared on the cover of Time accused of involvement in the Iran-Contra affair? "Yes it was that Khashoggi," explained Benson, the steward of the house, who finally appeared.

Before he fell out of favour with the Kenyan government, the Turkish-Saudi wheeler-dealer had used Ol Pejeta as a pleasure ranch. It was one of a collection of palatial homes stretching from Cannes to New York. It was a lifestyle thought to cost "AK" a cool $250,000 a day to maintain. Suddenly the scale and décor – giant canvases by 1970s Surrealists showing leopard-spotted cubes and a sideboard constructed from buffalo horn and ivory – made sense.

Despite its size, the ranch has only four bedrooms. Although a better description would be apartments. Mr Khashoggi's suite, overlooking its own swimming pool, is dominated by a bed so large it defies royal ranking. A dozen people could sleep comfortably in it – and probably once did. The tropical gardens are looked over by the jagged peak of Mount Kenya and patrolled by the martial-looking Marabou storks and skittish warthogs. A family of colobus monkeys haunt the tiled roof.

Benson confessed that he sometimes wondered what the high-living Mr Khashoggi would make of ordinary people using his house. "He had to abandon the place very suddenly. I think he would be very angry."

Today the house is run by the Serena hotel group, which seems to see it as a mid-range oddity, charging modest prices and providing, at best, mediocre food.

Eventually the house and its history will be ruthlessly refurbished, but in the meantime, just because a hotel chain doesn't understand the treasure it holds doesn't mean everyone else shouldn't.

Daniel Howden is Africa correspondent of The Independent