What is the fine-grained topic of the following text: The context for Graaff-Reinet and Langhuis is extraordinary: the protective dolorite pinnacles that rise above it to the south-west, as well as the river bordering its edge, have protected it from development which is why, for the most part, this Eastern Cape town is famously so well preserved. Only return the topic.
Preservation of the Eastern Cape town, Graaff-Reinet and Langhuis