Beyond being a transport hub, Centraal Station is a sight in itself. The turreted marvel dates from 1889. One of the architects, PJ Cuypers, also designed the Rijksmuseum, and you can see the similarities in the faux-Gothic towers, the fine red brick and the abundant reliefs (for sailing, trade and industry).
Built on an artificial island, the station was designed as a neo-Renaissance 'curtain', a controversial plan that effectively cut off Amsterdam from the IJ river. The garage in the right-hand wing was built to shelter the Dutch royal carriage, but it's rarely there (read: never). The area around the station always has loads of construction going on.