I don't believe about alien influence or it work towards other planets.But I believe that these places are concentrated with great energy.It works as a yantra like we wear day to day life but in a larger scale.They knew that as long as these concreted places are built they are done for life.They can live life without much obstacles.I believe this is the case with ruwanweliseya etc etc.It is energized with pirith and positive energy so the village people automatically benefit from it.They can live without much negative energy in their lifes+they automatically drive towards spiritual path.Most enlightened beings tend to leave their knowledge about universe in these constructions as in a form of energy.Because such knowledge cannot be translated into average people.Only those who are receptive can receive that knowledge.