Some amount of degraded walls at the Karnak temple in Luxor

The problems with historical structures is that the urge to preserve them (along with the financing and the technology) has only happened in the last few decades. For many historic monuments, the damage over the centuries to parts of their construction (or in some cases, to the whole monument itself) is so considerable that they cannot be restored. This wall where the structure seems so badly damaged is an example where there was no need to try and restore it.
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