Long-range angular correlations among particles may uncover physics beyond the Standard Model, such as Hidden Valley (HV) scenarios. We particularly investigate a QCD-like sector, where HV matter coupled with QCD partonic cascades, may enhance azimuthal correlations among final-state particles. Our examination at the detector level concentrates on discerning these signals at future e+e- colliders, which provide a cleaner experimental setting than hadron colliders. Particularly, the detection of ridge formations in the two-particle correlation function could suggest the existence of new physics phenomena.