Looking down on rooftops is something that often gives me a sense of where I am. Here are views from the highest point in Beijing:
The classic tiled curved roof lines show up somewhere in almost every rooftop picture I take in China. The Forbidden City probably has the highest density of them, but they are pretty common in other places as well. They are reserved for (or, perhaps, best preserved as) the roofs of temples and the homes of the wealthy. However, more modern buildings, such as hotels, will also have them to attract attention.
The shape, in older, traditional buildings, comes from the dougong construction method:
On the older tile roofs there will often be figures that are called “guardians”.
The more guardians the more important the building. The most important building in China, the Hall of Supreme Harmony has eleven.
All other buildings have ten or fewer.