In applying MR (AR/VR) technologies to cultural heritage sites, the design and implementation of mobile MR applications have mostly lacked a holistic and systematic approach in the viewpoint of retrieving existing content and providing personalized experiences to visitors on the fly. To address this issue, we designed and implemented the KCTM application in which various types of content from different databases are brought together and reorganized by a newly proposed metadata schema that assigns spatio-temporal information to them for the purpose of visualizing them in MR environments. According to the user evaluation, most of the participants expressed strong interest in touring the heritage sites augmented with various related content.