Valencia was first founded as a Roman Colony on the banks of the river Turia, in the year 138 BC. However it wasn’t until the Middle Ages that its walls began to grow along with the city – right up until the point that they reached the riverbed. These medieval walls, mostly completed in the 14th century, extended the perimeter of Valencia by around 4 kilometres – a clear sign of the economic prosperity the city was beginning to enjoy. The Serranos Towers were built between 1392-1398 by Pere Balaguer, a prominent local architect. Aside from the nearby Quart Gates, they are the only fortified entrance still standing from the 14th century.