At Citadel, we are committed to providing the value-added services which make your property operate more efficiently and effectively, with special attention to the bottom line. Our management business was founded on the principles of hard work, integrity, responsibility, accountability and transparency. In brokerage. Citadel has the knowledge, experience and a sophisticated understanding of the NYC market to assist you in marketing your property to gain the maximum exposure needed to attain the highest potential value.. We are specialists in the field of real estate brokerage, property management and new development marketing. Our clients include individuals, private investors, commercial entities, syndications, co-ops and condominiums.