San Pietro | Close up. On top the keys to the Kingdom of Heavens. 
My Latin is kinda rusty, but this is sort of what it says: 

Ioannes Paulus II P.M. Portam Sanctam anno jubilaei MCMLXXV a Paulo P.P. VI reseratam et clausam apervit et clausit anno jub. Humanae redemp. MCMLXXXIII ? MCMLXXXIV 

[Pope] Johannes Paulus the 2nd P.M. opened and closed the holy door in the holy year of humanic redemption 1983-1984, [the door that Pope] Paulo PP. the 6th reseratam and closed in the holy year 1975. 

Ioannes Paulus II P.M. iterum portam sanctam apervit et clausit anno magni iubilaei ab incarnatione domini MM ? MMI 

[Pope] Johannes Paulus the 2nd P.M. opened and closed the holy door in the great holy year of the resurrection of the Lord 2000-2001. 

I don't know what P.M., P.P. and reseratam mean, so I didn't translate that.