Through qualitative analysis of 80 student essays, the author examines geographic concepts students describe as holding traits of threshold concepts. With a group of 11 Honors students, the author employs metacogntion, asking students to analyze their own learning to discover their threshold concepts. Recognizing the role of liminality, this study suggests combining metacognition and geographic concepts to enable students to recognize their preconceptions, build or reconstruct their schemata and transform their understanding of a discipline. (Contains 1 table and 2 figures.)