Moi... where?
Administrative areas in descending order of size:
1. People's Republic of China 中華人民共和國 : 中华人民共和国
Zhōnghuá rénmín gònghéguó : Zung(1) fa(2) ngin(2) min(2) kiung(4) fo(2) guêd(5)
2. Guangdong Province 廣東省 : 广东省
Guǎngdōng Shěng : Guong(3) dung(1) Sên(3)
3. Meizhou 梅州
Méizhōu : Moi(2) Zu(1)
A prefecture-level city - note that the word 'city' here does not refer to a city in the usual English sense, but instead refers to a large administrative area, of a smaller order than a province, but larger than a county. Some may describe it as a municipality. It is divided into seven counties, of which one is Moiyan.
You can view the official Meizhou webpage in English at http://www.meizhou.gov.cn/en/
4. Mei County 梅縣 : 梅县
Méi Xiàn : Moi(2) Yan(4)
This then, is the 'Moiyan' I was interested in as a child, one of the seven counties within Meizhou municipality.
5. Meijiang District 梅江區 : 梅江区
Méijiāng Qū : Moi(2) Gong(1) Ki(1)
This is the main urban area enclosed within Meixian county.