Outer Manchuria

Short definition from Wiktionary

Proper noun

1. 1
   The part of Russia near northeastern China (including Primorsky Krai and other nearby areas) which was annexed by the Russian Empire in the mid 19th century understood as part of Manchuria; similar or equivalent to Russian Manchuria.
2. 2
   Used other than figuratively or idiomatically: see outer, Manchuria (a region of northeast China/Manchuria)
3. 3
   Any proverbially distant or remote place.