Millennials are changing public spaces through their use of technology and focus on sustainability and the environment. Current trends show rooftop gardens providing environmental benefits, nightclubs generating electricity from dance floors, pop-up stores benefiting neighborhoods, and no-tech spaces allowing relaxation. The document suggests opportunities for hotels like Marriott to incorporate sustainability features like indoor gardens and self-generating electricity systems to attract millennials by giving them incentives to socialize and feel they are helping the environment.