Careful restorations have returned Detweiler Meetinghouse — Ontario’s only surviving stone Mennonite meetinghouse — to its 1855 appearance, from its 12-pane window sashes to its original pine floors. The adjacent Roseville Cemetery has been in use since 1833. During Doors Open, staff from the Grace Schmidt Room of Local History at the Kitchener Public Library will be onsite with an informative display.