An useful index site I personally recommend for researching darknet sites.
“We provide an anti-phishing resource for darknet sites and record darknet history. We also track the uptime and downtime of darknet sites. This knowledge is important to many cybersecurity researchers.”
Links
Tor.taxi
http://tortaxi2dev6xjwbaydqzla77rrnth7yn2oqzjfmiuwn5h6vsk2a4syd.onion/