User blog comment:OverlordRocks/Where In Episode 3 Of NEXO Knights did it say it was one if the Sixteen Realms?/@comment-26381381-20160124203942

Inside the Fortrex,one of background is Lion Temple from Chima. So it means that Nexo Knights is co-existing with Chima. And Chima is part of those realms. See episode 3 in 12:30