As told by the yogi:-
"..... The human body is the temple. The top-centre of the head, "Brahma Kapalam" is equivalent to the temple's "Moolasthaanam" (sanctum-sanctorum). The human brain is just below the "Brahma Kapalam" ( top-centre of the head region). The human brain is covered by an extremely thin layer of skin. This white and red coloured human brain is not only encircled in multiple rings but also encompassed by ultra-thin red coloured nerves.This portion is also known as the "Sahasraara Chakra." In between the brain and the "Brahma Kapalam" there is darkness. God is situated in this tiny portion of darkness which is also referred to as the "Cave of Brahma". Therefore the "Moolasthaanams" (sanctum-sanctorum) in temples are designed to be dark, to depict the presence of God in the darkness between the human brain and the top-centre ("Brahma Kapalam") of the human head.(You may refer to the diagram above.)
Many ignorant devotees have commented that temples should be designed to allow plenty of air and light into the "Moolasthaanams." Not only that, many wealthy devotees have gone to the extent of re-building new temples that allow plenty of light and air into the "Moolasthaanams" which is blasphemous. Devotees, without proper understanding of the science and relationship between the human body and the temple should not involve in the construction of temples.
Kindly listen to my personal experience:-
Chingleput District is in the state of Tamilnadu. The most holy temple town, Sri Kanchi is situated in Chingleput District. I was born in this holiest of holy places called Sri Kanchipuram. In this temple town, there is a Siva Temple in the name of Sri Ekaambareeswara. This temple was built by great scholars of yore during ancient times. The author of this article ( Yogi Sachchidananda Yogeeswarar), that is myself, had visited the temple in the year 1875, exactly 55 years ago ( the year, 1920 of authoring this religious text). In the Saivite temples which were constructed in ancient times, the darkness used to spread gradually, starting from the Nandi itself. The darkness gradually spreads and increases in intensity as the devotee proceeds towards the sanctum-sanctorum ("Moolasthaanam"). I walked in such darkness and reached the "Moolasthaanam". I found a flickering ghee lamp only next to the Shiva-Lingam and not anywhere else on the way to the "Moolasthaanam". I have already explained the reason why a "Moolasthaanam" is required to be dark (just like the darkness between human brain and the top-centre of human head or "Brahma Kapalam" of a human being which is the place of God also known as the "Cave of Brahma".)
Temples which were built by knowledgeable devotees were designed to be pitch-dark in the sanctum-sanctorum, the darkness spreading gradually from the Nandi and intesifying as it reaches the "Moolasthaanam" where it is totally pitch-dark. Many such meaningful temples were destroyed 253 years ago in communal riots.
(To be continued............)