The area at the time of founding of the city was poorly drained and earliest development was on sloping ground along the left bank of a stream that is now the course of a trunk road (Julius Nyerere Way). The first area to be fully drained was near the head of the stream and was named Causeway as a result. This area is now the site of many of the most important government buildings, including the Senate House and the Office of the Prime Minister, now renamed for the use of the President after the position was abolished in January 1988.