The article focuses on the 'enclaves' of Balts, which were long preserved in Central and Eastern Belarus. In particular, such 'enclaves' existed in the vicinity of Gaina and Oboltsy.The Balts anthroponomy of the considerable part of the population of Oboltsy can be traced on the basis of the written documents dating back to a period of mid-15th - late 16th century. The fact that these Balts were not the Middle Age re-settlers from Lithuania is proved by the existence of burial mounds (kurgans) dating back to the 11th -12th centuries. In addition, during the archeological excavations the specific Balts artifacts were discovered. In the Middle Ages, the Balts settlements stretched from Gaina toward Radoshkovichi and Ivenets, which is proved by the numerous Balts' oykonomy. Grand Prince Aleksandr Kazimirovich, in his official letter of 1501, granted the right to the Bishop of Vilno to appoint Roman Catholic priests who 'spoke the Lithuanian language' in Radoshkovichi and Koydanovo. Close to Radoshkovichi, the archeologists studied the burial mounds/kurgans dating back to the late 11th- early 12th centuries, that were stone-faced and a zoomorphic bracelet, typical for the Balts, was discovered in one of them. The Balts-language speaking enclave was also located in the vicinity of the town of Dokshitsy, where numerous Balts oykonims were registered and similar Balts oykonims were also recorded southward from Minsk, close to Kletsk and Kopyl. The author believes that this medieval Balts' settlement was not part of the Lithuanian ethnic group, but represented the ancestors of the population of the Bantser archeological culture of the third quarter of the first millennium AD. He also launches an attempt to connect the relic Balts enclaves with the spread of ethnotoponims of the Latygol, Lotva, Litva-type. It is not ruled out that in the beginning, Latygol was used to name the northern part of the area of the Bantser culture while 'Litva' ethnotoponims designated the western border of annalistic Lithuania.