One of the Oldest religion is in the world Hinduism. The Hinduism has many gods and goddesses. But mainly focused on 3 Gods. The god Brahma is the Creator, The god Vishnu is the Protector and God Shiva is the one who maintains the discipline and destroyer.
The Consort of the God Shiva is Parvathi who is the god of blessing and Goddess Kali is another form of Parvathi who is punishing the wrongdoer. They have two sons- Skanda or Murugan, and Ganesh. The vehicle of God Shiva is Nandi a Bull. Therefor Bull or Cow has become a secret among Hindu society. The Indians they practice Hinduism widely.
In Sri lanka, there was no established religion in the pre-Buddhist period. But people had pre-Buddhist cults. Such as worshiping the trees, rocks, local deities and many more. Because people expect some unforeseen forces to help them in their life. They expect helps in difficult situations and as well as blessings. And The way of thinking it changed After the arrival of Buddhism. According to the belief of real Theravada sect of Buddhism. Buddha is not a god, he cants help us, every one of responsible for our deeds. What we have to do is just follow the path as a guideline which is shown by Buddha.
But even after Buddhism, some people continued some influences of the pre-Buddhist cult. Initially, They built Hindu temples according to early Hindu architectural styles. Especially Shiva temples. Buddhist people started to worship Hindu gods as well. It is very important to mention that Sri Lanka never ever faced with religious inventions or conflicts in history.And some of the Sri Lankan kings got married to Indian royal ladies who were Hindu. They come with many other peoples as well who follows Hindu religion with ought any local restrictions to follow their religion. Worshiping Hindu gods, Make and fulfilling vows in Hindu temples, Following astrology and auspicious times which denounced by Buddha.
11th century south Indians invaded Sri Lanka by cholas. and Shiva temples built by them. They ruled Polonnaruwa for many years, also they were Hindus. They Built at the entrance of Polonnaruwa citadel, Built by Rajendra Chola dynasty to commemorate his mother, they referred Polonnaruwa as Mummadi Chola Mangalam or Jananatha Mangalam as they develop the capital of Sri Lanka at medieval period. The symbol of veneration is phallus and yoni, symbolically Shakthi and Shakta which depicts the birth of a human.
At present most Hindu monuments of a Hindu temple according to the Dravidian architecture. A Gopuram is a monumental entrance tower, of a Hindu temple It is divided into many stories which diminish in size as the Gopuram tower rises. In the past buildings were not constructed above the height of temple Gopuram. Hindu deliverers spread over Sri Lanka about 10% of the population and most they are living in Northern, eastern . Jaffna, Trincomalee, Central Highlands, and Colombo.