Dialogue is "at the heart of the e-learning experience" (Littleton & Whitelock 2004, p.173). It is the means to building mutual understanding, encouraging the construction of personal meaning and ensuring engagement. Inquiry requires dialogue. If we value processes of inquiry, then it is at our peril that we ignore the complex issues and aspects of designing and facilitating in online environments for inquiry processes. How do we design online learning experiences that encourage dialogue and a process of inquiry? A phenomenological inquiry using student postings, student interviews and survey data from an online undergraduate course is undertaken to explore the dynamic interrelation between design, facilitation, tools and learning. As part of the analysis, a heuristic device was developed--the "Map of aspects of dialogical inquiry." In this article, this device and the dynamic interrelation between design, facilitation, tools and learning are discussed, and implications for practitioners teaching in online environments are explored. (Contains 3 tables and 3 figures.)