Hue, which was the imperial capital of Vietnam not so long ago, until 1945, has a number of tombs of former emperors around the city which are open for tourists. I went on a group tour that went to visit three of the main tombs all of which came in different styles though they were all built in accordance with “strict rules of geomancy” according to this website, our guide, and other sources. Here is one of them, Tu Duc Tomb.
A blog by Ayako Mathies 