Chester Rows

Chester Rows are a set of structures in each of the four main streets of Chester, in the United Kingdom, consisting of a series of covered walkways on the first floor behind which are entrances to shops and other premises. At street level is another set of shops and other premises, many of which are entered by going down a few steps.Dating from the medieval era, the Rows may have been built on top of rubble remaining from the ruins of Roman buildings, but their origin is still subject to speculation. In some places the continuity of the Rows has been blocked by enclosure or by new buildings, but in others modern buildings have retained the Rows in their designs. Undercrofts or "crypts" were constructed beneath the buildings in the Rows. The undercrofts are made from stone while most of the buildings in the Rows are timber.

Source: Wikipedia