A mountain range in Ningbo prefecture where the 四明 are clearly seen, i. e. sun, moon, stars, and constellations. 知禮 Zhili of the Sung dynasty is known as the 四明尊者 honoured one of Siming and his school as the 四明家 Siming school in the direct line of Tiantai. In Japan Mt. Hiei 比叡山 is known by this title, through Dengyo 傳教 the founder of the Japanese Tiantai School.

A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous

（地名）在浙江寧波。指要鈔詳解一曰：「四明乃慶元府南面山名，有峰最高。四六在上，每澄霽望之如戶牖，相傳謂之石窗。謂四畔通日月星辰之光故云四明。」大明一統志曰：「浙江寧波四明山，在府城西南一百五十里，周迴八百里，跨紹興台州之境。二百八十峰，其巔五峰絕高，形如芙蓉。」

丁福保《佛學大辭典》