Ninja Nation in Centennial, Colorado is open and a great destination for classes, birthday parties, open gym, homeschool gym and tons of ninja fun. Ninja Nation's ninja gym is one of a kind with world-class obstacles and the best place for a child's birthday party in Denver. Ryan Stratis and Rian McLean head up the coaching staff and lead a group of top-notch coaches to help both kids and adults get stronger, build confidence, all while having a ton of fun!