Walking down from the Prague Castle to Charles Bridge through picturesque narrow cobbled streets one comes across a narrow path between ancient buildings with the board Vinarna Certovka leading down a flight of steps to the river bank . This is the narrowest street in Prague - just possible for  people to walk in a single file ( I am not sure if a heavy built person would be able to walk through) and has now become a major tourist attraction.

Note the  traffic light has been fixed on both ends enable trouble free passage. Do make a point to walk down the street even if you feel that you wont be fit into the narrow path. The street where this is located - U Lužického semináre no. 24.