Šiauliai 1966

This is an illustrated Soviet military field post cover sent in 1966 from the post office Шяуляй/Šiauliai 2. The envelope has some nice pictures of Друскининкай / Druskininkai. Most of the field post sent from Šiauliai has a postmark of Šiauliai 4, because this post office was in Zokniai where the biggest military facility in the city, Zokniai military airport (presently used by NATO) was also located. However, Šiauliai 4 has opened sometime at the end of the 1960's so any mail prior to that was posted more from Šiauliai 2, one of the two post offices located in the center of the city.

Cancellations of Lit.SSR - 06 Soviet Military Field post

Вильнюс/Vilnius 1961 

back side with the Soviet military cachet and the arrival postmark of Leningrad

Каунас/Kaunas 1969

Those triangular military cachets are just hard to miss! These are stampless Soviet Military Field post, both sent to Ленинград/Leningrad (now Saint Petersburg, Russia). The first one is sent in 1961 from the post office Вильнюс/Vilnius 18 which was located near the military base at that time, and the second one sent in 1969 from the post office Каунас/Kaunas 17 which was located inside the military base itself. You will hardly see any civilian correspondences out of Kaunas 17.