Babban dutse

Dutsen ginshiƙi shine dutse na ƙarshe da aka sanya don kammala baka. Wannan dutse mai siffa na musamman wani abin al'ajabi ne na injiniya wanda ke da mahimmanci don tallafawa baka da kiyaye ƙarfinsa.
Alamar Keystone ba ta nan daga alamar Lodge, amma tana bayyana a cikin ma'auni na Babi. Ya yi adadi a cikin York Rite na digiri na Masonic a cikin Freemasonry a cikin bayyana almara na Hiram, maginin Maɓalli.