Train Tunnel and Track Expansion Set (LEGO 10425)

About this set

This is the LEGO DUPLO Train Tunnel and Track Expansion Set (10425), a 20-piece track-train scene kit rated 2/5 for difficulty. It combines an arch bridge, track and a switch into an expansion module that plugs into an existing DUPLO train line, with a signal light, triangular warning sign and flowers as scene extras. The palette covers grey, green, light green, orange, red, purple and white, with the bridge and track in grey-green and the sign and signal picking up red, orange and purple; the flowers sit beside the track. Build order: set the arch bridge supports first, then lay the track and switch, and finish with the signal, warning sign and flowers. At 20 pieces the part count is small, and the main challenge is keeping the two sides of the arch symmetrical and checking the switch connection direction before pressing the clutch together. It suits a child who already has a DUPLO train and wants a tunnel and a junction on the route, and it works well for a parent building the scene alongside them.