Originally, Nyingma teachings were propagated orally among a loose network of lay practitioners. Yogis, lay practitioners and vow-holding Ngakmapa practitioners were generally the earlier practitioners, while ordained monks and nuns and monasteries developed later. Padmasambhava is regarded as the founder of Samye Monastery, the first Buddhist monastery and Nyingma monastery in Tibet. Later, the Nyingma school's Six Mother Monasteries were built. Many of the Nyingma monasteries were destroyed before and during the Chinese Cultural Revolution, and most recently demolished as at Larung Gar and Yarchen Gar.