Messenger of the Lost World by binaryvision
This is a structure the humans built when they realized that all hope was lost... it contains all the knowledge that humans amassed over the time they had on earth. This machine is you could say the most intelligent robot ever built by humans, despite the fact that they had very little time to complete it and it doesn't necessarily look very sophisticated. It acts as somewhat of a time capsule for any race/species that might find it in the future... Many people say that our purpose in life is to live on through our actions/achievements/offspring... that's the idea behind this...
The tower at one point becomes conscious and starts to understand that it is a symbol of the death of an entire race and starts to attempt intergalactic contact. The irony is that it attempts contact in a human manner due to the data stored within - and after not being able to reach anyone it goes insane... (notice the screaming mouth on the top monitor)