Lugu Lake  is located in the northwest of the Yunnan plateau, with the middle of the lake forming the border between the Ninglang County of Yunnan Province and the Yanyuan County of Sichuan Province. The formation of the lake is thought to have occurred in a geological fault belonging to the geological age of the Late Cenozoic. It is an alpine lake at an elevation of 2,685 metres (8,809 ft) and is the highest lake in the Yunnan Province. The lake is surrounded by mountains and has five islands, four peninsulas, fourteen bays and seventeen beaches.

The lake’s shores are inhabited by many minority ethnic groups, such as the Mosuo, Norzu, Yi, Pumi and Tibetan. The most numerous of these are the Mosuo people (also spelt “Moso”), said to be a sub clan of the Naxi people (as per Chinese records of Minorities in China) with ancient family structure considered as “a live fossil for researching the marital development history of Human beings” and “the last quaint Realm of Matriarchy.” It is considered as the home of the Moso Tribe However, Mosuo have a separate identity from the Naxis, as it is said that the Chinese used the word Mosuoas a generic term for different ethnic groups, including the Naxi.

Lugu Lake is called the “mother lake” by the Mosuo people. The lake is also well known in Chinese travel pamphlets as the region of “Amazons,” “The Kingdom of Women” and “Home of the Matriarchal Tribe”, this last name highlighting the dominant role of the Mosuo women in their society. The marriage rites of the Mosuo people are known as “azhu marriage” ceremony and this unique aspect of their social culture has given the title “exotic land of daughters” to the area. It is also known as “A Quaint Realm of Matriarchy.” The matriarchal and matrilineal society of the Mosuos is also termed the “Women’s World.”

泸沽湖，亦称永宁海、左所海、勒得海、落水海子，是一个高原淡水湖，位于中华人民共和国云南省北部、四川省西南部，即四川省凉山彝族自治州盐源县与云南省丽江市宁蒗彝族自治县之间，横跨川、滇两省。湖泊东南面长满水草的大片湿地称为草海，广阔的水域称为亮海，湖面海拔2690米，面积48.45平方公里。泸沽湖是川、滇两省共管的湖泊，湖水透明洁净，属中国Ⅰ类水质，但环境问题也相当严峻。沿岸有中国知名度较高的摩梭人，他们的走婚婚俗在旅游界有很大的影响。泸沽湖风景秀丽，旅游业发达，是云南和四川两省的省级旅游风景区、中国国家重点风景名胜区。

泸沽湖水丰地肥，很早就有人在此聚居、耕种、生衍，沿岸及其周边居住着摩梭人、汉族、彝族、藏族、普米族、壮族、纳西族等10余个民族支系，其中以摩梭人和普米族人口最多。

泸沽湖是摩梭人的核心聚集地，湖边的摩梭人至今仍然保留着母系氏族婚姻制度，其典型民俗为走婚。无论是到过还是未曾到过泸沽湖的游客，在他们的印象中泸沽湖与摩梭人一般是相联系的，摩梭人的走婚和母系氏族风俗是吸引世人往泸沽湖观光的重要因素。摩梭人沿袭走婚习俗，与母系氏族的社会现象类似。