Koulurekisteri is the school history database operated by the Helsinki City Archives. It is the most comprehensive listing available of the history of all schools in the City of Helsinki area, starting from the founding of the city in 1550 up to present data. School names, related schools, historical principals, different buildings and current school archive locations are all listed for historical research purposes.
The Koulurekisteri UI is in Finnish, as it is geared towards local history aficionados. The UI uses a REST API that, however, can be used by English-speaking researchers.