Behind the Iron Gate Estate  was completed in 1965-1972. In the undeveloped after the War area, 19 monumental buildings, each of which counted as many as 16 floors, were built. The housing estate still covers large parts of Środmieście and Wola on both sides of John Paul II Alley. Its architecture and the construction style were oriented to settle the highest possible number of inhabitants and did so at the expense of convenience and comfort living. The resulting flats were mostly very small. Yet, the then innovative solutions such as full-height casement windows and parquet flooring were introduced here. To stimulate the local economy, the ground floors of the buildings were the space left for the purpose of establishing services and commercial activity. Behind the Iron Gate Estate blocks of flats are still inhabited by several thousands of people.