In Kerala prior to the British period, communication was extremely difficult. There were no roads, wheeled vehicles, or even pack animals. Travel and the transportation of goods depended on human porters and boats plying the numerous rivers and backwaters as well as the seacoast. Only local rulers and petty chieftains could ride on elephants or horses, and even then their use was primarily confined to processions. Since Indian independence and especially since the formation of Kerala State, roads have been built linking all parts of the state and all villages by bus. A railroad now links the southern city of Trivandrum to Mangalore in the South Kanara District of Karnataka (apart from links to Madras and the rest of India); there is one international airport (at Trivandrum) and two regional airports (at Cochin and Calicut). By the mid-1980s all of the villages were electrified. The settlement pattern in Kerala has always been dispersed, with the house of each landowner standing on its own patch of higher ground. The actual physical features of the countryside do not encourage the formation of compact settlements, though today there is a tendency for some parts of settlements to hug the roads. It is impossible to tell where one Village ends and another begins. The ideal Malayali house was set in its own compound with its food-producing trees, so that the dwelling space did not subtract from cultivation space. Formerly (prior to the twentieth century) the large Nayar house, set in its own compound with its walls for protection, was a veritable fortress. Nambudiri Brahman houses as well as middle-class Tiyyar houses followed the same pattern. Every home had a name and the individuals belonging to a given house were known by that name. The members of low and Untouchable castes attached to a Nayar house were known also by the name of that house. Today settlements are still dispersed, though because of population growth many of the spaces in between have been filled in.