As hinted at by Fred the Shed, railways (lines/ embankments/ telegraph poles/ signals/ signal boxes/ stations/ water towers/ coal stores/ engine sheds/ bridges/tunnels / rolling stock in sidings etc. etc.) If you leave out overhead electrification (hassel to model/wargame with) the line are good for most line up to mid 1960s, for some line (out of the way country lines OR reenactment line such as the Severn Valley) even up to present day.