Sark is a tiny, car-free island in the English Channel that didn't fully get rid of feudalism until 2008. Its nights are so reliably dark that it's just been named the world's first "dark sky island", making the island one giant observatory for looking up at the night sky without any light pollution to get in the way.
The Einstein Tower in Potsdam, Germany was built by architect Eric Mendelsohn between 1920-1921. The tower, which researches solar magnetic fields, was inspired by Albert Einstein's study of relativity, but it's unknown whether Einstein approved of its design.
New digital light-filtering technologies make it possible for city-dwellers to build astronomical observatories into the rooftops of their homes, complete with high-powered telescopes. Today's New York Times has the story: