Jainism in Kerala

Jainism, one of the three most ancient Indian religious traditions still in existence, has very small presence (0.01%) in Kerala, in south India. According to the 2011 India Census, Kerala only has around 4500 Jains, most of them in the city of Cochin and in Wayanad district.
Medieval Jain inscriptions are mostly found on the borders of Kerala proper, such as in Wayanad in the north-east, Alathur in the Palghat Gap and Chitharal in Kanyakumari District. Epigraphical evidence suggests that the shrine at "Tirukkunavay", perhaps located near Cochin, was the major Jain temple in medieval Kerala (from c. 9th century CE). The so-called "Rules of the Tirukkunavay Temple" provided model and precedent for all other Jain temples of Kerala.
Some of the Jain temples in Kerala were incorporated by the Hindus at a later stage. The temple images are worshiped as Hindu gods and considered as part of the Hindu pantheon. It is not uncommon for Hindus and Jains to worship their deities in the same temple.
History.
Jainism in Iron-age/early historic Kerala.
It is possibility that Jainism arrived in modern-day Kerala in the third century BCE soon after Maurya emperor Chandragupta Maurya (died "c." 297 BCE), accompanied by Jain sage Bhadrabahu I, made the pilgrimage to Sravana Belgola (in present-day Karnataka). Their followers might have journeyed further south, into present day Tamil Nadu and Kerala.
A number of caves, donated by the early historic Chera chieftains to the Jains, can be found in the Karur-Pugaliyur region of western Tamil Nadu. Utiyan Cheral Atal, a Chera chieftain, is stated to have ("Akam" 55, "Puram" 65 and 66) died by starvation through a practice (the vattakku-irikkal) similar to the Jain "sallekhana vrata". Utiyan Cheral was wounded on the back by his Chola rival Karikala in a battle. 
Late medieval to early modern Kerala.
Ilamko Atikal, who is traditionally credited as the author of the Tamil epic "Chilappatikaram", was probably a resident of a Jain vihara known as "Kunavayir kottam". Some scholars identify Kunavayir kottam with Tirukkunavay[il] or Trikkana Matilakam, now known as Matilakam, a village near Cochin. Matilakam was also known as "Gunaka" and "Kunaka" in the medieval period ("Kokasandesa", slokas 45-48). Archaeological excavations conducted at Matilakam in 1970, revealed an 8th-9th century CE foundation, structurally different from the standard Hindu temple foundations in shape.
Whether it was the same as the kottam at Kunavay or not, epigraphical evidence suggests that the shrine at Tirukkunavay was the major Jain temple in Kerala. It is assumed that the so-called "Rules of the Tirukkunavay Temple" provided model and precedent for all other Jain temples of medieval Kerala. A dating system known as the Tirukkunavay Era was also present during this period.
Inscriptions mentioning the Tirukkunavay
Based on the Talakkavu Temple Inscription, it is calculated that the Tirukkunavay Temple was founded some time at the close of the 7th or the beginning of the 8th century CE. It seems that by 15th century, the Tirukkunavay Temple was transformed to a Siva temple ("Kokasandesa", slokas 47-48). The deity of Kunaka is called "Purari" in the poem "Kokasandesa". The location of the temple is now lost to the scholars (the temple was probably destroyed completely in late medieval period).
Other Hindu temples in Kerala with Jain characteristics are
Jainism in modern Kerala.
Some Jain shrines from early historic and medieval times still remain, notably in Jainamedu, near Vadakkanthara, Palghat, and in Sultan Battery in Wayanad. Koodalmanikyam Temple in Irinjalakuda is believed to have been a Jain temple. The assumption is that it was dedicated to Bharateswara, a digambara Jain monk. Some Jain temples located in modern-day Kerala are: Anantnath Swami Temple (Puliyarmala Jain Temple) in Puliyarmala, outside Kalpetta, Jain Temple, Kidanganad, Wayanad, Jainimedu Jain Temple, Kattil Madam Temple, Jain temple, Alleppey, Kallil Temple in Perumbavoor, Dharmanath Jain Temple, Mattancherry, Shri Vasupujya Swami Jain Temple, Srinivasa Mallan Road, Kochi, Cochin Digambar Jain Mandir, Panampilly Nagar, Kochi, Chathurmukha Basati, Manjeshwar and Parswanatha Basati, Manjeshwar.