Fanjunkars is a reconstructed croft linked with Aleksis Kivi, Finland's national writer. Kivi lived at the original Fanjunkars in the 1860s and early 1870s, a period connected with some of his most important work.
The original building was destroyed during the Porkkala lease period, so what you see now is a reconstruction rather than a preserved house. It is still a worthwhile literary stop, especially if you have read Seven Brothers or want a more Finnish reason to come to Siuntio.