The unexpected discovery of an elaborate stone coffer with lowland-style carved images and early Maya inscriptions in a cave in the northern Guatemalan highlands has great implications for our understanding of highland-lowland interaction. However, this discovery proved to be only the “tip of the iceberg” in terms of the importance of subterranean evidence in this region. Investigations in caves in central Guatemala over the past decade have been a central part of the regional investigations, often directing subsequent reconnaissance, settlement surveys, and site excavations. Indeed, the early history of the region and the trade route passing through it has largely been reconstructed from evidence in cave shrines along the mountain valley routes from Kaminaljuyu and the Valley of Guatemala to lowland Maya sites. This article reviews this evidence, which also demonstrates how cave assemblages can be used not merely to study ancient ritual, but to examine broad problems in culture history and critical elements in the study of elite power, ceramic production, settlement patterns, interregional trade, and ancient economy.