On the main road to billionaire Gautam Adani's planned Vizhinjam mega-port on the southern tip of India, a shelter built by the coastal region's Christian fishing community blocks the entrance, preventing further construction.

The simple 1,200 square-feet structure with a corrugated-iron roof has since August stood in the way of ambitions for the country's first container transhipment port — a $900 million project that seeks to plug into the lucrative shipping trade flowing between juggernaut manufacturers in the East and wealthy consumer markets in the West.

Decorated with banners proclaiming "indefinite day and night protest," the shelter provides cover for roughly 100 plastic chairs, although the number of protesters taking part in the sit-ins on any one day is usually much lower.