IPA: /ˈprɒmənˌtɔːri/
KK: /ˈprɒmənˌtɔri/
A high area of land or rock that sticks out into a body of water, often providing a view of the surrounding area.
The lighthouse was built on a promontory to guide ships safely to shore.
Promontory → It is formed from "pro-" (meaning before or in front of) and "montem" (the accusative form of "mons", meaning mountain). A promontory is a high point of land that juts out into a body of water, literally meaning a mountain that projects forward.
Think of a 'mountain' ('montem') that 'juts out' ('pro-') into the water — that's what a promontory is.