The fruit shape colora and leaves remind me of POMEGRANATE ...
It is * Punica granatum...*
Punica granatum tree may indeed have * spines* on branches...
Since its in a park, May be you can keep an eye on it and photograph
> ZZ Unknown 009 Tree - Fruit.jpg
> ZZ Unknown 009 Tree - Leaf.jpg
> ZZ Unknown 009 Tree - Spine.jpg