The earliest worship was conducted in naturally-formed caves. This reflects humility of the ego in prayer. Being underground, one is closer to mother earth and is protected by the womb of the earth.
The arches are laid for the main hall
Meditation is where one seeks to make conscious contact with God or the source of all light and energy, and is largely a practice in silence. Below the ground, there is pindrop silence and stillness, making an environment that is highly conducive to meditation.
Below-ground structures enjoy constant temperature - with relative cool in summer and warmth in winter. The structure is also bushfire proof and earthquake sound, within limits. Finally, and perhaps most appealingly, the rooftop is available for recreation. At the Mukti-Gupteshwar Mandir complex, the roof has been covered with grasses and gardens so that children can play and devotees can relax, socialize and enjoy a meal in the Sydney sunshine.
Some scenes from the grounds of the complex shortly after construction
The following picture shows an architect's impression of the complex. This image was created before construction. The main temple is where the diagonally arranged series of small white circles can be seen. Those white circles are in fact skylights into the temple. Most of the area is available for recreation. The look-and-feel of the surrounding scenic area is not only preserved but enhanced by the tree-planting and the dam with its fountains.
Architect's impression of the Mandir complex before construction