WOOD, NOT CARDBOARD - Our 6 Stacking City Buildings are made out of wood, not cardboard! Designed to last. 6 COMMUNITY HELPERS THEMED BUILDINGS - Includes Museum, Hospital, Fire Station, Police Sation, School, and Recycling Center FITS OVER YOUR TOY TRACKS - Each building has openings on opposite sides so they can fit over your wooden train tracks, or your diecast cart tracks! BUILDINGS NEST TOGETHER FOR EASY STORAGE - The 6 Town Buildings nest together easily so they can be easily stored during clean up without taking up space in your toy box! REAL WOOD DESIGN, SAFE + NON TOXIC FOR KIDS - Nesting Community Helpers Building Boxes are all compliant with US Safety Standards