The central company hospital of Loeboek Dalam was founded by the tobacco company Deli Company. Its area was 13,135 ha. This plantation was situated in Down Langkat, 15 km southeast of Tandjoengpoera (map p.87 of the Grote Atlas van Nederlands Oost Indie). Loeboek Dalam is mentioned by E. van de Velde in his articles “Het hospitaalwezen op Sumatra’s Oostkust”, published in Het Ziekenhuis (1918). The hospital was founded before 1900, as there is a picture dating 1900 (KITLV beeldbank 18302).
Langkat was a self-governing Landschap, situated in the Government Eastcoast of Sumatra. It was divided into two subdepartments Upper Langkat and Down Langkat. Together they count 256,000 inhabitants, of whom 1,400 Europeans and 30,600 Chinese. The assistant-Resident and the Sultan reside in the capital town Tandjoengpoera (Gonggryp 1934, 724).