You can search through images of hundreds of works on the Public Art Archive, “a totally free, continually growing, online and mobile database of completed public artworks.” Recently celebrating their 10-year anniversary, this site is a treasure trove of public art to be inspired by.
According to their website, the purpose of the archive is to:
gather documentation about public artworks into one central repository;
provide opportunities to inform diverse audiences about the breadth and depth of what constitutes public art today;
support best practices in cataloging public art;
raise awareness about the value of public art;
showcase the diversity of public artwork types and functions;
provide a digital platform for sustained engagement with public art;