When and where was Romeo and Juliet originally set?

William Shakespeare identifies the setting of Romeo and Juliet in his opening words as the Chorus says, "In fair Velona where we lay our scene."  Romeo and Juliet takes place in Verona, a city in Italy, in the 1300s (although the play itself is believed to have been written around 1592). 
The play consists of both interior and exterior settings during both daytime and nighttime.  One of most significant interior settings from the first act is the ballroom where Romeo and Juliet first see each other.  It is significant that Romeo (who, with his friends, is often seen outdoors) has come to the ball without a proper invitation, on the urging of his friends who hope the beautiful women there will help him to overcome his love for Rosaline. 
Another significant interior setting is Friar Lawrence's cell, where the two lovers meet through the efforts of both the Friar and the Nurse.  There they finalize their plans to marry and to create the ruse of Juliet's feigned death.  It is significant that this is one of the only places Juliet, a sheltered young woman (not yet 14), can venture outside of her home. 
Juliet's bedroom, where the marriage is consummated in secret, is another significant interior setting as is the mausoleum where Juliet (having taken a potion to appear dead) is entombed until Romeo finds her and kills himself (leading, of course, to Juliet's real death). 
The outdoor settings are equally significant.  It is in the outdoor square that Tybalt kills Mercutio and Romeo then kills Tybalt, leading to Romeo's banishment and hastening the plot of marriage and feigned death.  We revisit the same outdoor square when all is revealed as the play ends and the two mourning families finally make peace.