In the 1960s, after the sixth Buddhist council had given Mahasi Sayadaw an eminent role in the Buddhist meditation revival, he was invited by the Sri Lankan government to train, teach and help establish vipassana meditation centers in Sri Lanka. At that time a group of already well known meditation monks received the opportunity to privately train and practice with Mahasi Sayadaw. Among those was the Venerable Matara Sri Ñāṇārāma Mahathera.
Mahasi Sayadaw made him the main vipassana teacher after his departure and a friend of Matara Sri Ñāṇanārāma Mahathera invited him to lead the training facility for meditation in a newly founded association of forest monasteries, the Nissarana Vanaya.
Over the years Ven. Ñāṇārāma Mahathera added valuable instructions to the Burmese system. One of the fundamental additions was a greater emphasis on concentration meditation as well as a carefully designed set of standardized instructions which helped newly ordained forest monks to methodically develop their concentration and insight faculties.
Many influential meditation teachers visited the monastery during this time (Ayya Khema) or were influenced by its meditation methodologies.
During the last decade of Ven. Ñāṇārāma Mahathera's life the meditation system was refined in its approach towards labeling and noting in vipassana meditation. The amount of labels was reduced, the importance of concentration meditation intensified.
Currently this system is taught in many of Sri Lankan forest monasteries which were influenced by Ven. Ñāṇārāma Mahathera.