Refers to narrow, often hidden or less-traveled alleys behind main streets. The cross-reference 路地裏 is a more common synonym.
See also: 路地裏
I found a small izakaya in a back alley.
Back alleys at night are a bit scary.
Compound of 裏 (ura, 'back') and 路地 (roji, 'alley'). The reading is straightforward.