General terms:
* Outskirts: This is a common and neutral term, simply meaning the outer parts of a town or city.
* Periphery: This word implies a boundary or a less important area on the edge.
* Fringe: This suggests a less developed or marginal area on the edge of a settlement.
More specific terms:
* Suburbs: This refers specifically to the residential areas that lie outside the central urban core.
* Rural-urban fringe: This term describes the transition zone between urban areas and rural areas.
* Hinterland: This refers to the area surrounding a city or town that is influenced by it, but not part of it.
Figurative terms:
* Margins: This emphasizes the edge of a settlement, suggesting a space where things are different or less developed.
* Frontier: This implies a more adventurous, unsettled area at the edge of a settlement.
The best word to use will depend on the specific situation and the tone you want to convey.