If you have ancestry from eastern Brandenburg — the portion of the former Prussian province lost to Poland after 1945 — then you’ll be interested to know that there’s a German foundation dedicated to the preservation of the history and culture of the region. The name is “Stiftung Brandenburg,” and the website URL is:
Among the available services if you can visit in person are day tours with a guide, some of which are available in English. The location of the Brandenburg House is: Parkallee 14, 15517 Fürstenwalde (Spree), and further information can be obtained by writing to: <firstname.lastname@example.org>.
Specific information about available tours can be obtained from Veronica Kölling, at:<email@example.com>. Also consider visiting to see scheduled exhibitions. An example (which would be of interest to the newly formed German-Australian Genealogical Partnership) would be this one:
“The emigration of Ostbrandenburgern to Australia in the 19th century.”
A museum is open four hours daily, Monday through Friday, while a library is open five hours daily on Tuesdays and Thursdays. New books acquired for the collection are displayed from time-to-time at this URL address:
…which may give you Brandenburg researchers some ideas of what new resources you’d like to see!