Revelation Space by Alistair Reynolds

Nine hundred thousand years ago, something wiped out the Amarantin. For the humans now settling the Amarantin homeworld, it's of little more than academic interest, even after the discovery of a long-hidden, almost perfect city and a colossal statue of a winged Amarantin. For brilliant, ruthless scientist Dan Sylveste, it's more than merely intellectual curiosity - and he will stop at nothing to get at the truth.

Even if it costs him everything. But the Amarantin were wiped out for a reason, and that danger is closer and greater than even Syveste imagines . . .