The suffix -sthan (nep.) means place or location. My idea is that each Place (Area) in the City should be represented by at least one picture of a Temple, a Shrine, a Chaitya and Sculptures.
Map in http://www.kathmandu.gov.np/en/node/105
Your comments and fotos please to info@kathmandu-valley-temples.com
Ratna Pustakalaya
Foto by Shankar Giri in https://english.onlinekhabar.com/ratna-pustakalaya-kathmandus-historic-library-loses-its-appeal-in-modern-times.html