#sacred architecture

• Absidiola — A small, secondary apse that usually opens into the main apse or the transept arms of a Christian church, housing a secondary altar or sacred relics. In the hermeneutics of religious space, the absidiola functions as a devotional micro-universe, a space dedicated to intimate meditation, penitence, or the veneration of particular ethical values embodied by saints.
• altar — The most important and sacred part of a place of worship, usually located in the eastern section of Christian churches, separated from the nave by the iconostasis, where the priest celebrates the liturgy and performs religious sacraments; alternatively, an elevated stone or wooden table or structure in antiquity or various religions upon which sacrifices or ritual offerings were made to a deity.
• Apse — A monumental semicircular, polygonal, or rectangular recess, vaulted in the shape of a semi-dome, located behind the nave of a Christian church or at the back of an ancient Roman basilica, housing the imperial throne or the liturgical altar. In astronomy, it designates either of the two extreme points (closest or farthest) of the elliptical orbit traveled by a celestial body.
• Apsidal — Pertaining to an apse, relating to an apse, or having the shape of an apsidal structure; a vaulted or semicircular architectural element specific to the altar of Christian churches. In structurally applied astronomy, the term describes the imaginary line connecting the farthest or closest points to the center of attraction in the elliptical trajectory of a celestial body.