Chicago’s Newest Improv Theatre The Chicago Improv Den (CID), which officially opened Spring of this year, offers the rare chance to study improv with small class sizes, built-in performances and an incredibly hands-on owner and founder, Dina Facklis. On the theater’s website they make it clear that they are not a “replacement for iO, The Second City, CIC or the Annoyance” but rather an “advanced supplemental training program.”