The picture above is not showing Hanavský pavilon, but the view from Hanavský pavilon. There is actually a restaurant in this peculiar structure, but I warn you right here not to try it. It is totally overpriced and in my experience, the personnel is not very friendly. And, on top of it, the view you can enjoy without going into the restaurant. However, the structure of the pavilion and its history are quite interesting.
The structure was built as a promotion of an ironwork factory for the exhibition in 1891 and was considered a temporary structure which should last only for the time of exhibition. However, it was considered a valuable technical development, and after the exhibition it was disassembled and rebuilt in a present location in Letná park. It is the first structure in Prague built from a cast iron, concrete and glass. It was designed in baroque style and it is surviving more than 128 years longer than originally planned.
So I recommend visiting this place when the sun goes down, because Prague during the last light of the day or just after sunset is beautiful. To check whether you would be interested in the pavilion structure itself, you can look at its pictures