Step 1: A grid iron street pattern is a type of city planning where streets are laid out in a grid-like pattern, with streets intersecting at right angles. This design is typically used to improve navigation and organization.
Step 2: Chandigarh, a city in India, was designed by the famous architect Pierre Jeanneret and Le Corbusier with a grid iron layout to facilitate the urbanization of the city.
Step 3: Philadelphia in the United States is also known for its grid iron street pattern, which was established during its planning in the 17th century.
Step 4: Cairo and Venice do not have grid iron street patterns. Cairo's streets are more organic and less planned, and Venice is known for its maze-like narrow streets and canals.
Conclusion: The cities with a grid iron street pattern are Chandigarh and Philadelphia.