Smilsu (Sand) Street was the widest and most important street in Old Riga in the 13-17th centuries, following the Great Sand Road outside of the city. Smilsu (Sand) Street in the 13-17th centuries was the broadest and the most important street in Riga – it was the continuation within the city of the so called Great Sand Road. In the 13th century it was the only land road on which it was possible to enter Riga. It began at the Sand Gates of the city wall, next to which there was the Sand Tower (since the 17th century known as the Powder Tower). The name was probably borrowed from the opposite high hummocks, the so called Sandy Hills. In the Middle Ages on Smilsu Street there were two common wells and at the end of the street there was a market where coal used to be sold.