Stoomtrein Katwijk Leiden (formerly Stoomtrein Valkenburgse Meer, abbreviated SVM), is a 700 mm (2 ft 3+9⁄16 in) narrow gauge heritage railway line around the Valkenburgse Meer in the south of Katwijk, Netherlands.
Although the name translates as Steam Train Valkenburg Lake, technically actually trams are used for the tourist attraction.
From the starting point Vrieze Wei, not far from the city center, volunteers started in 1973 to operate a steam train line on the tracks formerly used by the dune water company, which abolished the transport of goods using these railways through the dunes.
Having bought steam- and diesel locomotives from companies also ceasing their activities on narrow gauge railroads, the passenger carriages were built on site by the volunteers themselves.
The narrow-gauge foundation decided to create a museum with a heritage tramline.