Star Wars Planets No. 3: Coruscant
One cannot underestimate the importance of the seat of the Republic and, later, Imperial power. The Republic’s collapse began in the Senate chamber with the vote to elevate Sheev Palpatine to Supreme Chancellor. It was all downhill from there.
Anakin would complete his journey to the dark side in the Chancellor’s chambers, and later murder younglings in the Jedi Temple. Palpatine would rule the Galaxy from there. That is, until he made the overconfident decision to oversee the final stages of the Death Star II’s construction personally. (Thank you, Bothans!)