Behind this door is one of London’s most extraordinary interiors.

The deceptively modest entrance to 575 Wandsworth Road.

From the outside it’s the entrance of a nondescript terraced house on raffish Wandsworth Road. But as I stepped inside I stopped and gasped. Suddenly I was in the Cordoba mosque or a Yali villa beside the Bosphorus. Every surface was riot of intricate fretwork: patterns dazzled, figures danced, strange symbols beguiled.

The opposite side of the front door. Two small saws used to create the decoration are displayed low down on the left.

I took a seat at the kitchen table in the dimly-lit basement; an Arab lamp cast shifting shadows over walls covered with pots, plates and pans. I learnt that the house’s owner, Khadambi Asalache, began by carving a piece of wood from a skip to cover damp seeping from the launderette next door. After that, he just didn’t stop.

Asalache (1935-2006) was the son of a Kenyan Masai chieftain and grew up reading Shakespeare while herding goats. Fiercely intelligent, he worked his way through studies in Nairobi, Rome and Vienna before arriving in London to become a civil servant at the Treasury. He soon established a routine. Every weekday he’d carve for three to four hours. At weekends he’d be busy with his knife and fretsaw for 12 or more. Hall, bathroom, kitchen, bedrooms…one by one he completed a room then moved on to the next.

Asalache’s partner, an artist with her own residence, endorsed the decision to leave the house to the National Trust. Over recent years it has been conserved; it opened to the public in March. She describes the rooms as being just as though he’s momentarily stepped outside.

Jars of spices in the kitchen hint at Asalache’s love of cooking and entertaining. CDs piled in the sitting room reveal his fondness for music from classical to “world”. And books on every subject imaginable speak of his passion for literature and his endlessly curious mind.

There’s a pair of colourfully-embroidered slippers and a dog kennel beside the bed. Collections of ceramics include Victorian “warming plates” with compartments for boiling water underneath. Everywhere you look there’s something to intrigue and make you smile.

I’d go so far as to describe this house as a symbol of what makes London the best place in the world to live. A person arrives from overseas and enhances a city that is as eccentric, original and endlessly fascinating as he proves to be.

Book in advance for 575 Wandsworth Road. Tickets until 31 August all sold out shortly after going on sale in March. The next tranche (September to November) is available on Thursday 1 August. Get your finger ready on your mouse!

The sitting room. Alarmingly, Asalache had candles everywhere.

Patterns on every surface, including the floor.

Interior images courtesy of David Clarke for the National Trust.