London, it seems, has a mining centre (7)
I believe the answer is:
capital
'london' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for capital that I've seen before include "savings" , "Finance - excellent!" , "It's terrific in the big city" , "Metropolis" , "Hamilton, perhaps" .)