This sounds like they're working on a cathedral in the twelfth century. Historically, masons were stone workers and bricklayers. In the present day, "mason" means a member of the Freemason fraternal organization.
No. A mason is a stoneworker. They're probably not very common in Australia/Canada/US/New Zealand these days, but they still exist in Europe working on old buildings. And even in the new world we have some older buildings using stone.