FIG (Ficus)
Since the leaves of this tree don't match F. carica and F. carica also needs male and female trees for pollination and this is the only tree, it's likely this is an F. carica cultivar.
This might be "Ficus carica 'Calimyrna' (Smyrna type)" as shown here (scroll almost halfway down the page), or something else entirely:
http://waynesword.palomar.edu/arbimg10.htm
F. carica gallery:
http://luirig.altervista.org/pics/index4.php?search=Ficus+carica&page=1
And, unusual pollination by wasps explained:
https://gobotany.newenglandwild.org/species/ficus/carica/
"Their flowers are actually produced inside the package (syconium) we think of as the "fig." Tiny wasps live inside the syconium and lay their eggs there, incidentally transferring pollen from flowers of one syconium to another. When the eggs hatch, the flightless males mate with the females, and chew a hole through the syconium through which the females escape to fly to another syconium and carry on the cycle. Don't worry, though; you're unlikely to swallow a wasp when you eat a fig; they will have flown the coop by the time the "fig" is ripe."