To add onto what Jonathan discovered I've also found the footer nav bar contains a link to the old PeeringDB URL as well.

Additionally I found that on the participants page the link to the Northern Lights Gigapop organization doesn't work. I am not sure if there is a web server issue at the UMN or if the target URL (http://www.northernlights.gigapop.net/) is just out of date but I get a TCP reset when attempting to connect on port 80.

dig snip

;; ANSWER SECTION:
www.northernlights.gigapop.net. 17743 IN CNAME  nlg.webhotel.umn.edu.
nlg.webhotel.umn.edu.   17743   IN      A       160.94.254.29