Announced where the Colossus was? That’s progress! (7)
I believe the answer is:
inroads
'that's progress' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for inroads that I've seen before include "Progress" , "Encroachments" , "advances" , "raid" , "Sad iron (anag.)" .)