Diego Martin is a town and is the urban commercial center and capital of the Diego Martin region in Trinidad and Tobago. Its location in the region is just on the south eastern border, west of the capital city of Port of Spain and east of the town of Carenage. Diego Martin town in the Northern Range was once filled with a number of small valleys but is now a densely populated area. It was named after a Spanish explorer Don Diego Martín. The area was settled by French planters and their slaves in the 1780s. It consists of a cluster of communities including Congo Village, Diamond Vale, Green Hill, Patna Village, Petit Valley, Blue Range, La Puerta Avenue, Four Roads, Rich Plain, River Estate, Blue Basin, Water Wheel, West Moorings, Bagatelle and Sierra Leone.