The resemblance observed in mosques situated throughout the Islamic globe is the merging of old Christian architectural design with contemporary Persian technology. For Muslims, the mosque is a place of worship. The mosque's design exemplifies Islamic culture. Thus, the similarity between so many geographically separated mosques is not surprising. Within the Islamic world, there are several regions with a predominance of mosques. One such region is the Ottoman Empire. Mosques were built throughout this vast area by Turkish rulers who were influenced by their Persian counterparts. In addition to being a place of prayer, the mosque also serves as a memorial to the holy prophet Muhammad. Old mosques tend to look more like churches while new ones resemble giant shopping malls. This transformation has been going on for years and will likely continue to evolve. There are several reasons why medieval Christians designed their buildings in the Islamic world. First of all, they were using existing designs so they weren't copying anyone else. Also, they lacked expertise in architecture and had to rely on others for guidance. Last but not least, they could afford only a limited amount of construction materials which forced them to use what was available instead of designing something from scratch. Looking at examples of medieval mosques around the world, we can see that they often have identical or similar elements. This is because medieval architects didn't follow any particular style.