strong point

(ordnance) A strongly fortified and heavily armed point in a defense system, usually supported by auxiliary armed positions.

noun

Something at which a person excels: forte, long suit, métier, specialty, strong suit. Slang bag, thing. See ability/inability.

Also, strong suit. An area in which someone or something excels, as in That beautiful lobby is the building's strong point, or Writing is her strong suit. The first term was first recorded in 1840; the variant alludes to various card games, in which it signifies the suit with the highest or most cards.

Definition: strength
Antonyms: weakness

(DOD, NATO) A key point in a defensive position, usually strongly fortified and heavily armed with automatic weapons, around which other positions are grouped for its protection.