 King Otto 's early reign was notable for one more reason : He moved the capital of Greece from Nafplion to Athens . His first task as king was to make a detailed archaeological and topographical survey of Athens . He assigned Gustav Eduard Schaubert and Stamatios Kleanthis to complete this task . At that time Athens had a population of roughly 4 @,@ 000 – 5 @,@ 000 people , located mainly in what today covers the district of Plaka in Athens . 
