The Leprosy village of  Lao Si Momo (Spring Water) was founded on August 25, 1906 in the Batak region of Sumatra by the Nederlandsch Zendeling Genootschap (Netherlands Missionary Society). It was established some 10 kilometers from the town of Kaban Jahe. See KIT image collection 1935 TMnr 10001259.

From: Geillustreerde Encycopaedie van Nederlandsch-Indie: ‘ Kabandjahe, main town of the sub department Karolanden, department Simeloengoen en de Karolanden, Government Eastcoast of Sumatra. The town on the mountainous Karo region with a rather cool climate is popular by tourists and people seeking for health revalidation.’

From: ‘Comprehensive Atlas of the Netherlands East Indies’, p. 76: The location of Lao Is Momo, south of Kabandjahe may be noticed.

From the annual reports by the Civil Medical Service 1909: The Government Decision of 16 December 1907 no. 14 accorded an amount to the leprosy asylum at Lao Si Momo, in the country of the Karo-Bataks on the Eastcoast of Sumatera.At that time 132 leprosy patients had been admitted. By building some addditional houses the situation of housing improved greatly. De missionary-teacher at Kabandjahe continued to care for the asylum.

From the Sumatra-Post of 12 September 1922: in an article by von Romer this leprosy facility was mentioned. ‘On the Karo-Batak plains many cases of leprosy are found. The local population is cruel in isolating them rigorously. Since some 15 years the Leprosy colony of Lao Si Momo has been  founded and cares for some 150 patients. A Batak head of the colony has been chosen who suffers also from leprosy. The NI Government provides for a periodic medical check and for a small subsidy per inhabitant. The missionary J. van den Berg is in charge of the Colony.’

The hospital still exists nowadays and is registered by the Ministry of Health (nr. 1211033). It has 60 beds for the leprosy patients. It is managed by the Province of North Sumatera.
Its director is dr. Emmi Suriani Simbolon. (Data year 2014)