* Depopulation: This refers to a decrease in population size.
* Emptiness: This suggests a lack of people or inhabitants.
* Desolation: This implies a state of being empty or deserted.
* Rarity: This refers to the uncommonness of people in a particular area.
* Isolation: This indicates a lack of interaction or contact with other people.
The best antonym will depend on the specific meaning you want to convey. For example, if you're talking about the decline of a city's population, "depopulation" might be the most suitable term. But if you're talking about a remote island with few inhabitants, "emptiness" or "desolation" might be more appropriate.