Tammela is a municipality of Finland. It is located in the Tavastia Proper region. The municipality has a population of 5,834 and it covers an ar…Tammela is a municipality of Finland. It is located in the Tavastia Proper region. The municipality has a population of 5,834 and it covers an area of 715.15 square kilometres of which 74.72 square kilometres is inland water. The population density is 9 inhabitants per square kilometre. The first mention of a village named Tammela was in documents from 1423.