The star exhibit at Germany’s oldest astronomical observatory is the 21m-long refracting telescope (the world’s longest), built in 1896 by astronomer Friedrich Simon Archenhold. Other exhibits are a bit ho-hum but still impart fascinating nuggets about the solar system, astronomy in general and the history of the observatory. Kids love having their picture taken next to the big meteorite chunk.
Between October and March, you can look through the big telescope at 8pm on the second and fourth Friday of the month.