On the one hand, some dilapidated structures are doomed to be demolished due to the fact that they pose potential danger to those living in. Shabby shelters, for example, are less likely to withstand the storms or other safety hazards. Also, the needs of the inhabitants in such dwellings cannot be fully satisfied because of the lack of maintenance and renovation. By contrast, the modern buildings are usually well-designed, with upgraded safety standards and improved appliances. However, this does not mean that all the old constructions should be removed, or that all of them do not deserve protection or preservation at all.   

On the other hand, the efforts to maintain and repair the old, historic sites are （猜词互动） for several reasons. The primary reason is that many old architectures are significant historically and culturally, and therefore are considered as the cultural heritage of any particular nation. Buildings such as these are important windows for people to understand their past and learn from history. Another reason lies in the fact that countries all across the world are actively promoting their unique historical architecture to high-spending tourists, who tend to be drawn by the cultural significance of these tourist destinations, bringing in hard currency and thus boosting the economy in these regions.  

In summary, my view is that not all old buildings should be replaced by modern ones: while those dangerous should be knocked down and new ones should be constructed, those with historical significance should be better maintained and preserved.