By Gary Duffy
BBC News, Sao Paulo
There can be few prouder homeowners in Sao Paulo than Estevao Silva da Conceicao, who has spent more than two decades building a house that has become his lifelong passion.
The "Casa de Pedra" - the House of Stone - is one of the most unusual places in the city, and is to be found in the heart of the shanty town of Paraisopolis.
It is a magical place of archways peppered with stones, and walls covered with every kind of imaginable object from plates, cups, and statues, to typewriters and mobile phones.
It was built in a space of just 75 square metres (807 sq ft) and is eight metres (26ft) high.
Inside, a warren of stairways and tiny corridors lead to a roof garden at the top of the house which has an impressive view of the favela that is home to more than 70,000 people.
What seems most striking is that a man who had never heard of the Catalan architect Antoni Gaudi has built something so similar to his style.
The facade at the front has often been compared to features in the world-famous Parc Guell in Barcelona.
Estevao, 50, simply set out to build a house where he could live, and which later became a home for his wife and two children.
It was only seven years ago when a passing architecture student spotted the house that he became aware of the connection between his work and that of Gaudi.
Estevao has since travelled to Spain, to see Gaudi's work himself, and his home in Paraisopolis has become an attraction in its own right.
Earlier this year, the interior of the house featured on the front of the Brazilian edition of Vogue's home style magazine.
The project began in the simplest of ways.
"I planted a rose tree and it got very big, and I built the structure of the house in a way that would allow the tree to grow... I replaced it with other trees, and I never stopped planting and building.
Estevao was amazed when he finally got the opportunity to travel to Spain.
"When I arrived in the Parc Guell, it's then that I thought that the work was very similar to my house. And I thought, wow, how could I have built something so like his work without ever seeing it."
Gaudi's designs shattered architecture conventions of the age
Estevao's wife, Edilene, says she is very proud of her husband.
"I think the house is very beautiful and different and the children love it," she says, adding that she does not mind all the visitors who drop by.
Estevao did all the work on his own, and after 22 years he says he still has a lot to do.
His ideas have evolved over the years and the design often changes.
"When I first built the house using wood, people used to say it looked like an indigenous or Indian house. Then I started to change, and the structure is made with iron."
Paraisopolis is a favela that sits right in the heart of the wealthy district of Morumbi in Sao Paulo.
It is an area that has seen some improvements recently, but over the years it has had its fair share of violence, and life has often been a struggle.
Estevao says everyone in the shanty town knows where the House of Stone is.
Estevao says his house is important for the community
"It's very important for the people in the community who appreciate art; for the ones who understand and like art, and we have visitors from many countries."
Using basic everyday material, sometimes retrieved from the rubbish, this kind of project is sometimes call "spontaneous architecture".
It involves a visionary project, carried out without following any rules, by someone with no formal training.
Estevao started to work in the fields of his home state of Bahia, in north-east Brazil, when he was just 10 years old, before moving to Sao Paulo when he was 19 to work as a builder's assistant and then a gardener.
In a country where the millions of people build their own homes, Estevao has created a unique project in a completely unexpected place.