As a classifier, 座 is used for large, immovable objects like mountains, buildings, bridges, and towers. It differs from 所 (for houses/institutions) and 栋/幢 (for standalone buildings) in that 座 emphasizes the object's size and fixed nature, not just its structure. As a noun, 座 means 'seat' or 'base', overlapping with 座位 (zuòwèi, the general word for a seat) and 位子 (wèizi, a specific spot like a restaurant seat).