Peat is either charred in pits and heaps, or in kilns.
"Peat and its Uses as Fertilizer and Fuel" by Samuel William Johnson
He moreover manufactured pitch and tar, in a little kiln or pit dug for the purpose close by his house.
"Toronto of Old" by Henry Scadding
At the east base were brick kilns, clay pits and much marshland.
"The Young Continentals at Bunker Hill" by John T. McIntyre
A brief history of kilns reveals they range all the way from a fire pit dug in the ground to big industrial-sized kilns for firing rows and stacks of plates, cups, whatever.
Identifying where in the kiln pitting happens will help determine what to do about the problem.