海边(hǎi biān) - seaside in Mandarin

海边 (hǎibiān) is the seaside, the strip of land right by the sea. 海 (hǎi) means "sea" and 边 (biān) means "side, edge", so the compound is as literal as English "seaside" itself.

It shows up most in holiday and leisure talk: 去海边度假 (qù hǎibiān dùjià), "go to the seaside on holiday", and 在海边散步 (zài hǎibiān sànbù), "walk along the seaside". 海滩 (hǎitān), "beach", is the narrower word for the sandy strip itself, while 海边 covers the wider coastal area, promenade included.

边 (biān) is a productive suffix worth flagging on its own: it appears in 那边 (nàbiān), "over there", 旁边 (pángbiān), "next to, beside", and plenty of other location words, always adding the sense of "the side/area of".