Within the Daozang, the overarching architecture is expressed through the “Three Grottoes” (San Dong), which function as the primary spiritual and textual horizons of the tradition. These are known as Dongzhen, Dongxuan, and Dongshen, often rendered as the Grotto of Perfection, the Grotto of Mystery, and the Grotto of Spirit or Divinity. Each grotto gathers a distinct stream of revelation and practice, so that the canon mirrors the inner diversity of Daoist experience rather than a single, uniform path. The arrangement is not merely bibliographic; it encodes a vision of graded access to the Dao, from more rarefied contemplative teachings to ritual, talismanic, and therapeutic arts.

The first of these, Dongzhen, the Grotto of Perfection, is associated with the Shangqing or Highest/Supreme Clarity corpus. Texts in this division emphasize meditation, visionary and visualization practices, and celestial revelations that guide inner alchemy and spiritual transformation. Here, cultivation is oriented toward transcendence through refined inner work, and the scriptures present detailed methods for engaging with subtle realms. This grotto thus represents a pinnacle of esoteric teaching, where the practitioner is invited to align inwardly with perfected realities.

The second, Dongxuan, the Grotto of Mystery, is linked to the Lingbao or Numinous Treasure scriptures. Its focus lies in ritual and liturgy: communal ceremonies, cosmological visions, and practices of universal or cosmic salvation. Within this grotto, Daoist religiosity takes on a more collective and ceremonial form, emphasizing ethical conduct, ritual propriety, and the harmonization of human communities with the larger cosmos. The texts here show how Daoist insight is enacted through formal observances that weave individual destinies into a broader salvific pattern.

The third, Dongshen, the Grotto of Spirit or Divinity, gathers texts associated with the Sanhuang, the Three Sovereigns, and older layers of Daoist practice. This division emphasizes talismans, exorcistic rites, protective methods, and healing and therapeutic techniques, including medical and ritual technologies aimed at safeguarding life and extending longevity. In this grotto, the Dao appears as a living power that can be invoked for protection, cure, and the regulation of subtle forces. Together, the Three Grottoes are further supported by supplementary groupings, yet their core structure already reveals a canon that spans contemplative ascent, ritual communion, and concrete engagement with the spirit world.