Why is it that when a city is abandoned, it is not surrounded by a wall and they do not try to preserve it?

There are several reasons why abandoned cities are often not surrounded by walls or actively preserved:

**Resource Limitations**: It can be expensive and resource-intensive to maintain and preserve an abandoned city, especially if there are no plans for future use. Without funding or a clear purpose, preservation efforts may be neglected.

**Lack of Interest**: Many abandoned cities may not hold historical significance or appeal to the public, resulting in little interest in preservation. Without community or governmental support, such sites often fall into decline.

**Environmental Factors**: Over time, natural elements like weather, vegetation, and wildlife can reclaim abandoned areas, making preservation difficult. Urban decay can lead to structural instability, further complicating preservation efforts.

**Ownership Issues**: Abandoned sites can have unclear ownership, especially if they were once owned by private entities or if the owners disappeared along with the inhabitants. This can deter potential preservation efforts.

**Cultural Perspectives**: Different cultures have varying attitudes toward ruins and abandoned places. Some societies may see them as part of a cycle of life, where buildings and cities naturally decay and are reclaimed by nature.

**Safety Concerns**: Abandoned cities can become dangerous due to collapsed structures, toxic materials, or other hazards. This concern can limit access and discourage preservation efforts.

**Historical Awareness**: In some cases, there may be a lack of historical documentation or awareness regarding the significance of an abandoned site. If the history is not valued or recognized, preservation efforts may be overlooked.

**Urban Development**: In many cases, the land on which abandoned cities sit may be repurposed for new development. Cities often prioritize economic growth over preservation, leading to the demolition or neglect of these sites.

In summary, while some abandoned cities do receive attention and preservation efforts, many are left to decay due to a combination of financial, legal, environmental, and cultural factors.