YOU SAID:
let's go to saint peterburger
INTO JAPANESE
聖ペテロブルガーに行きましょう
BACK INTO ENGLISH
Let's go to Saint Peter Burger
INTO JAPANESE
聖ペテロ・バーガーに行きましょう
BACK INTO ENGLISH
Let's go to Saint Petersburgers
INTO JAPANESE
Saint Petersburgに行きましょう
That didn't even make that much sense in English.