This impressive tree is growing on a square of the historical centre of Paraty town, Brazil.
The fruit ( looks like something edible but it isn't) or seed pod is big with a diameter of about 15cm.

What a spectacular tree Myriam!

I've been through the list of trees on the following site, Abricó de macaco (Couroupita guianensis) comes close but the leaves aren't toothed. It could be in the same family.

http://www.arvores.brasil.nom....

It's a Brazil nut, more photos at the bottom ..

http://en.wikipedia.org/wiki/C...

Couroupita guianensis was in full bloom the time I was there, Janet.
Cannon Ball Tree (Couroupita guianensis)
It could be in the family like you said! I'll see what I can find..

Couratari guianensis does have toothed leaves!

http://fm2.fieldmuseum.org/pla...

http://fm2.fieldmuseum.org/pla...

http://fm2.fieldmuseum.org/pla...

It doesn't grow naturally in Brazil, but street trees are brought in from elsewhere according to usefulness.

I've checked other species of Couratari but none look correct.

There are trees in your set of photos which have both mature fruits and flowers at the same time Myriam. It seems the nuts take a long time to mature.

There's a pdf describing Couratari guianensis which you can open on the first link of google Myriam (rngr.net) which says:

Annual flowering occurs during the rainy season, July through September, when the tree is leafless

https://www.google.co.uk/searc...

Could this be an old cultivar?

Yes that's right Janet that the photos I took in the database have both seed pods and flowers.
Curiously the seed pods of the old tree have a similar shape to the flower buds of Couratari guianensis, but I'm sure they were seed pods not flowers, some were fallen on the floor and they were heavy and hard!

The Couratari guianensis or Cannon Ball tree perfectly round seed pods didn't look the same as from the tree I posted,
Also the ones of the Canon Ball Tree were growing on the stem. It does look very different in general shape of my tree too.

The leaves though do look similar..

Sorry , cross-posted I'll have a look at your link..

I think the nuts take a long time to mature Myriam, so you will often get both flowers and fruits at the same time.

Thanks Janet,
From the same pdf document you gave a link of :

The bark is light brown,
dark brown, or red brown (grayish brown in shade) and lenticellate
(lenticels round to elongate), with vertical cracks and
slight longitudinal fissures

The bark of my tree doesn't has those features..(I mean the 'vertical cracks and slight longitudinal fissures')
I'm also confused because we're talking about two different trees: Couratari guianensis and Couropita guianensis ?..The seed pods of Couratari guianensis don't look like mine being so elongated.
True that the seed pods on my tree look young but still they were distributed along the branches none along the trunk of the tree like in Couropita guiannensis.

Ooops! The genus name is sooo similar!

The leaf description on the pdf says it's entire which means no serration.

That still makes me wonder if the tree is a cross between two species in the same family! The nuts look so much like Couroupita guianensis!

Well, it could be possible it is a veeery old crossing, who knows..I think the tree might be as old as the time the Portuguese colonized Brazil and founded the city..

I decided to search for trees used in street planting in Paraty Brazil! I found it!

A tree from Southeast Asia which was planted in a park in Paraty, the elephant apple (Dillenia indica)...

http://www.geographylists.com/...

https://www.google.co.uk/searc...

That is definitely THE one Janet!
I had done a similar search something like 'trees in Paraty town' but it didn't lead me anywhere..

I am so impressed!

I have been likened to a Terrier Seedfork, an affliction I am unable to help.