Railway station Haarlem.
This picture nicely shows the beautiful roof structure covering up the tracks. Its lightweight construction was made possible by taking advantage of the most recent improvements in steel production and design methods of the time. One detail in this respect is visible here at the bottom of this support beam: it rests on a metal cylinder, like today's highway bridges and viaducts, allowing limited but secure movement, a real innovation at the time (beginning of the 20th century).
Still, lightweight meant 1700 tons of steel...