||The benefits of using light emitting diode (LED) lighting for landmarks extend beyond energy savings to the use of illumination for creating visual identity, placemaking, and increasing tourism. While measuring energy consumption is possible with metering technologies, thereby quantifying savings in energy costs, quantification of the social impact of landmark lighting is not straightforward. Measuring and monitoring social impact metrics is key to stakeholders investing in new connected LED lighting systems or upgrades of conventional lighting in order to realize the benefits of lighting that are beyond energy sustainability. We consider social sensing as an approach to quantifying social impact of landmark lighting. Using lighting at the Empire State Building and Bay Bridge as case studies, social sensing querying and data analytics aspects are presented. A number of practical lessons and technical directions for the use of social sensing in connected landmark lighting are then laid out.