Moving back as far as the Roman times, in ancient Rome Man has started using stone to protect drain

The layman term for drain cover (grate) is manhole cover. Say "manhole cover" and pictures of spies/heros making use of the underground sewage system popping out of manhole cover in Hollywood films appear.

Historically from the time that Man invented the sewage system since the Roman Times to drain water and urban waste away for sanitation purposes, manhole covers (drain covers or grates as we prefer to call them) have been invented out of the basic need to avoid people from falling into underground sewage and to prevent large objects from entering the drains which cause choking which eventually can result in flooding.

Fast forward to the present day, the sewage system is still in under all cities all over the world. Instead of the crude stone manhole covers the Romans used in the ancient days, now have special steel reinforced stone gratings that provide the thousand year old function of covering the inlets of our sewage system.

Much more than a cover, check out Jonite's range of drain covers (drain gratings) here: