Why did Weiyang Palace and Jiaofang Temple Palace in Han Dynasty become ruins?

China pays attention to geomantic omen, and it is definitely not allowed to go to the places of the former dynasty. In addition, the war in the late dynasty was easily destroyed by war. Most of them used to be herpes zoster, so they couldn't stand for a long time. Look at the current Forbidden City, which was also renovated after the founding of the People's Republic of China. During the Republic of China, it was also shabby, and it should be said that it was completely renovated.