Jitka Cvancarová (Lída Klasnová) & Petr Vanek (Jonás Hromek) also worked together in The Painted Bird (2019) as Ludmila & Nikodem respectively.
The village of Protejov is in reality Velke Karlovice. At Protejov train station, there are signs indicating that the railway line leads to Vsetin and Velke Karlovice. This is true in reality because the station is actually Velke Karlovice Halt ('zastavka' in Czech). Velke Karlovice is near the Czech-Slovak border and this is reflected in that fact that some characters speak Czech and others Slovak.
Doktor Martin is based up the hit UK TV Series Doctor Martin which was itself a spin-off of Portman's hugely successful movie Saving Grace.