The Spis basin (northern Slovakia) east of the high tatras and surrounded from the south side by the Slovak ore mountains, created favourable conditions for human settlement. Iron age finds are frequent. Three bloomeries for iron production found in spis have been evaluated on the basis of furnace construction and the chemical and structural analysis of slag. The use of refractory lining enabled higher temperatures to be reached in the furnaces. The metallographic examination of iron objects (axes, a dart, hammer) is described. This reveals that the ancient metallurgists understood the properties of the bloomery iron produced and knew how to select material for differing purposes. Photographs, drawings. References. -- ICCROM