The world's largest station by number of platforms is Grand Central Terminal, Park Avenue and 42nd Street, New York City, USA, built from 1903–13 which has 44 platforms. They are situated on two underground levels with 41 tracks on the upper level and 26 on the lower. The station covers 19 ha (48 acres), and on average some 660 Metro North trains and 125,000 commuters use it every day.
There is also a secret platform below the Waldorf Astoria hotel, next door to Grand Central Station. The belief is that this was used by President Franklin D. Roosevelt, to leave the hotel (after giving a speech) in his wheelchair, but hidden from view. This abandoned platform was never used in regular service, but as a loading point, coincidentally under the hotel.
Of the 19,000 items which are collected in Lost and Found each year, 60% are returned to their owners. Perhaps the most unusual items include a basset hound, a pair of prosthetic earlobes and a deadman's ashes (left there on purpose by his widow as he used to use the excuse of falling asleep on the trains to cover his extramarital affairs!).
Comments below may relate to previous holders of this record.