Is there a smaller model railway gauge than N?

There are a couple of gauges smaller than N gauge, the most recognised being Z and T gauges.

To give you an idea of the difference between gauges, N gauge track has a distance of 9 mm between the rails while Z gauge has a distance of just 6.5 mm. T gauge is by far the smallest commercially available gauge sporting a distance of just 3 mm between the rails. T gauge pushes the boundaries of what's possible in the world of model railways with its locomotives being so light that they require magnetic wheels and steel rails to operate!

Although Z gauge has managed to secure a niche following since Marklin first introduced it in 1972, T gauge remains predominantly a fascination of Japan.

Modellers of Z and T gauge model railways often choose such a gauge to challenge their skills as opposed to a desire to model a whole city on a 6 ft baseboard. And although the ingenuity of manufacturers means trains can perform reasonably well rushing or even trundling through the landscape, modellers looking for smooth starts or shunting fun should probably stick to N gauge or larger.