The house with a gable roof but no basement was built of stone. The preserved external stone staircase ends with the so-called "baladur", a small covered terrace with the entrance to the residential part of the house. On the northeastern facade there is still a chimney-like annexe, which once served for the oil- making purposes. The external characteristics of the house are concluded by the simply elaborated stonecutting details of the windows and entrances, and by the gutter-shaped tiles on the roof. The interior of the house has been also preserved in full. Prior to the restoration, the groundfloor rooms served for agricultural, fruit growing, wine growing and oil-making purposes, while in the 19th century there was an oilery in them.
A part of Tona's House is also the former outhouse, which is today used as a washroom and a depository for various ethnological tools and implements, while the olive trees and the mulberry trees - the latter are very old indeed - only complement the image of a original rural home in Istria.
The type of the oilery as presented in the Tona's House ethnological collection at Sv. Peter, was in the past two centuries prevalent all over Istria. The technological process of oil-making in such oileries demanded the following appliances: olive grinding mill, press (with which ground olives were pressed), spindle for tightening press screw (as auxiliary implement), and stove with cauldron, in which water was boiled. The arrangement of the above mentioned tools was strictly purposeful, for it enabled the work to be carried out rationally.
Istrian oileries were often owned by individuals, but in some areas they were built by village communities - from here the so-called "communal" oileries - or even parishes.
The oilery proprietor employed three or four oilmen, mostly his relatives or fellow villagers, as well as some seasonal workers who came from distant villages and returned, when the season was over, to their homes. Work was carried out in winter, when olives were ripe.
The mill, in which olives were ground, was circular and made of stone. Its upper part was shaped like a shallow plate and made of large stone slabs. Into the centre of the stone plate, a concave stone plate with a metal bearing was built. In it, a wooden spindle was set, with its other end inserted in the ceiling beam, so that the spindle could turn smoothly around its axis. Through it, a wooden pole was inserted horizontally, to which a millstone was attached, so that it rolled on the plate. The millstone was driven by animals (ass, horse, or ox), or even by men, especially in oileries with smaller and lighter millstones. In mills, situated by rivers or streams, the millstones were driven by water. In more recent times, however, electricity was used. Olives were thrown directly under the millstone or into a wooden tub, connected with the drive shaft, from which olives slided steadily on to the grinding surface.
Ground olives were put into round bags, made either by oilmen from hemp or coconut ropes or bought in Koper or Trieste. The bags were placed on a stone pedestal under the press screw. The workers weighted them with wooden stocks, poured boiling water over them and began with the pressing procedure. Boiling water speeded up the extraction of oil from olives. As long as it was possible, the screw was turned manually. Then the spindle was used, connected with a rope to the horizontal wooden pole and the pressure screw. When the spindle was turned, the rope spun on it and pulled the wooden lever, due to which the pressure of the screw on the bags containing ground olives increased. Once the olives were pressed, the workers removed the screw, loosened the pressed olives, again poured boiling water over them and repeated the whole procedure.
Oil was scooped from the barrels by shallow metal plates, while waste water, olive husks and the remaining oil ran into the space beneath the oilery, which is in this reconstruction indicated in the opening with the two barrels. Oil was sometimes additionally boiled in copper cauldrons, for it was believed that in this way it would get a better aroma and taste than the unboiled oil.
The rural kitchen and the room are not a true copy of such rooms in a certain historical period, but contain primarily the objects as well as equipment and furnishings as used in former centuries and in the first half of the 20th century, when life by the fireside was still alive. At first there prevailed home-made equipment or equipment made by village craftsmen, but in the course of time these objects were replaced, especially in richer houses, with furniture as used in towns, as well as with little household implements bought in shops. Various applicable and ornamental textile articles, e.g. embroidered tablecloths, curtains and bed spreads, were made at home still in the 19th century, and it is also known that after World War I, courses organized for such purposes were attended by village girls.
