Empire Market is late, original and developing for the ceiling of darknet marketplaces on the onion.
It has almoust all of it's central features from now Alphabay. And claims itself a replacement of it.
The legitimacy of It's mirror can be verifiable by using the tor marketplace's own link-verifier webpage http://empiremarket-url.com/.
If URLs links are not working, here is the onion mirrors where you can discover working darknet marketplace mirrors http://empiremarket-url.com/