Kerala is quite known for its pilgrimage options that it offers. These religious sites have strong myths that are deep-rooted and even legends. These are tales that has been over one thousand years. It's not hard to look for a church, temple or even a mosque. Houses for worship are almost present in each corner and nook. Here are some of those:
HINDU: Sabarimala- This is found in Pathanamthitta. It is very well known for their deity Ayyappan or Lord Dharmasastha. They believe the son of Vishnu and Lord Shiva. The latter god is saintly and is in meditation every time. Another god that they believe in is darshan, whom they offer forty one days in each year. They call it the Mandalam Pilgrimage, this has been second to the first largest pilgrimage worldwide. Furthermore, they have gathered more than three hundred millions of their devotee. To find their temple, you can go to the hilltop that's famously known as the Sannidhanam, which means an abode that's scared. It is surrounded by seven hills each major and minor.
CHRISTIAN: For the reason that Kerala has been one of the very first places reached by Christianity, they are remarkably established. When the first batch of immigrants who are Christians went to Kerala from Syria, they were tormented by the Romans and the Jews. The series of events happened so fast that Catholicism was established in Kerala. Given this fact, you can see churches or chapels every one hundred meters of distance. Some of them are historic and so you should probably check with their local residents to have better assistance. Identify which of their many churches are historical.
ISLAMIC: Due to relations in trading together with the west of Asia, it has brought the advent of Islam along its shores. The formation of Arabia followed and it was done through Arab Traders. The people believed that it has arrived in Kerala in about six hundred anno domini. This is during Mohammed's lifetime. Another interesting fact is that the Islam in Kerala is quite different from the Islam in other countries. They are educated highly and are always out in positions that are deemed to be very important. Due to this high status, it certainly shows in their infrastructures. You will see sophisticated designs.
JEWISH: The largest community is composed of the Jews. In the time of the Crusades, Jerusalem's fall cause most of the immigrants who are Jewish to take and find refuge in the hills of Kerala. One of its late emperors invited the refugee to settle and stay in some areas of Kerala. After several years, the Jews established and built synagogues. It is available for sightseeing however you won't be able to visit on Saturdays if you are a non-Jew. This is their Sabbath day and that is their day of worship.
Do your research before going on to these places. Each of them have a peculiar culture, an own set of rules that even tourists should follow to pay respect.