portal and madrasah in the registan of samarkand seen through the hole of a grate

religion registan architecture mosaic dome uzbekistan decoration portal building facade travel gate arch madrasah tourism landmark sherdor islamic complex unesco silk road madrassa tile entrance tilya kori ulugh beg madrassah central asia tilla kari uzbek ozbekiston madrasa ceramic tillakari cupola sunny tilyakori timurid registon frame samarkand hole grate