Many people and much general research believe that such megalithic sites were used for solar cults, religious worship, or similar activities etc, without fully comprehending that each site was built for a specific function: i.e. an energy function. Stonehenge in the UK, for example, had a function to channel energy that was made available according to specific times/events of cosmic phenomena. Thus, the site had to be correctly aligned for these precise energy emissions.
All over the world there are sites that show the function of channeling energy - be they stone circles, single stones (dolmens), sacred groves, hills, shrines, etc - all together they made up an earth-grid to carry and distribute the cosmic energies along the earth . Many Christian churches, for example, are built upon these sites, once considered pagan sites, for the 'old knowledge' once knew of this function. Larger structures, such as cathedrals like Notre-Dame and Chartres, acted as energy-accumulators (like batteries), which is often indicated in their design by the use of spirals or labyrinths in their construction.
The important element in energy storage and transmission is that cosmic energy flows at particular times of the year, and thus the 'old knowledge' made use of this in the original Christian calenders. By this I mean that this knowledge was reflected in the names of the saints to which different churches are dedicated (although much of the system is now misunderstood and mixed around). Each day of the year was attached to a particular saint so that the original purpose was for the entire community to gather at the church for their saint's day - a day that represented the time when the maximum energy was available in that area during the year. Likewise, festivals in specific places in the countryside, along with established pilgrim routes, enabled a line of transmission to be enabled whereby people would act as the channel, or conduit, for passing along the energy, thus maintaining the energy flow within the earth-grid.
This system is still in place, although 'humans-as-facilitators' is now a weakened system of transmission and the functional use of many places has been weakened. However, the earth-grid is still firmly in place and is pulsed regularly with cosmic energies, both according to natural cosmic alignments as well as specific and deliberate 'energy-feeding' from external and intelligent interventions...
The 'Light-Grid' is currently undergoing a harmonic and vibrational upgrade, both to serve as casting off the negativity of the 'Dark-Grid' as well as preparing Earth and humanity for rising vibrations akin to consciousness aligned with fifth-dimensional reality.