This is № 414 of Pilentum's model railroad videos. Although HO scale and N scale are the most popular scales for model railroading, the market for railway modelling in TT scale is growing. So it is not a surprise to discover beautiful designed model railway layouts with steam locomotives and diesel locos in TT scale.
Video № 149: Model Railway in HO scale of Switzerland.
Video № 148: The City of Hamburg in Germany as Model Railroad Display in HO Scale.
Video № 147: Model Railway Layout in HO scale with German Landscapes.
Video № 143: Model Railroad of Denmark in HO scale.
Video № 131: Very Large Model Railroad Exhibit in Northern Germany in HO scale.