The Soviet Union once built many sanatoriums along the coast of the Black Sea, especially on the Crimea Peninsula, which was a very famous and important health resort for the Soviet Union.
The secret sanatorium of the KGB, or more precisely, a secret mental hospital, was not quite suitable to be established on the Crimea Peninsula. Thus, it made perfect sense to set up a less conspicuous secret sanatorium near Odessa, an important port city rather than a tourist city.
And there is indeed a sanatorium on the southern coast of the Odessa city area shown on satellite maps. It hasn't been renamed something trendy like a vacation center; it retained the very era-specific name of sanatorium.
That's why Brian would sometimes get tense and sometimes happy because of this sanatorium.
