In 454 BCE what treasure was transferred to Athens ostensibly for security reasons.?

In 454 BCE, the Delian League's treasury was transferred from Delos to Athens. This move was ostensibly made for security reasons, claiming that it would protect the funds from potential threats. However, it effectively marked a shift in power, reinforcing Athens' dominance over the League and its member states. The transfer symbolized Athens' growing influence and control in the region.