Here is the next smaller option for N gauge layouts.  Each kit forms and island that can be linked with other islands using Unitrack to make a unique and compact layout. No special tools are needed to assemble the base. A small screwdriver forfastening the screws and glue are all you need. Special materials for creating landscapes can be purchased separately.
 
Package includes:
・Curved Track 183mm x 1
・Line fixing screws 
・Diorama base
・​Terrain form
・an instruction manual　
・Straight track S124 (1)
・Line fixing screw
・Diorama base
・ Styrofoam
・Instructions(Japanese)
The instructions are detailed with illustrations. They are easy to make even if you cannot read Japanese.