The Holy 108
The Divya Deśams ('divine places') are the 108 temples mentioned and glorified by the twelve Āzhvārs in the Nālāyira Divya Prabandham. A temple becomes a Divya Deśam by virtue of being sung by an Āzhvār — the sacred verse creates a permanent bond between the place, the Āzhvār's devotion, and the Lord who resides there.
Geography
Of the 108 Divya Deśams, 105 are in India (concentrated in Tamil Nadu, with others in Kerala, Andhra Pradesh, Karnataka, and Uttarakhand), one is at Muktinath in Nepal, one is in the transcendent Vaikuṇṭha, and one is in the cosmic milk-ocean (Tiruppāṟkadal). The most celebrated are Śrī Raṅgam, Tirumalai-Tirupati, and Kāñcīpuram.
Pilgrimage Ideal
Circumambulating all 108 Divya Deśams is a supreme aspiration. Each deity has a unique name, a specific Āzhvār hymn (pāsuram), and distinctive divine qualities celebrated at that place. The maṅgaḷāśāsana tradition — wishing the Lord auspiciousness — is central to Śrī Vaiṣṇava piety and is expressed most purely at the Divya Deśams.