Public transport of Narita Airport (NRT)：N'EX, Skyliner, Airport Bus TYO-NRT

Narita Airport is the major international airport in Big Tokyo area.
The easiest way to downtown is by either Keisei railway or JR-East railway.
If you travel with big suitcase, bus is a better choice than the train.
The bus options are Limousine bus, Tokyo Shuttle and The Access Narita.

Public transport in Tokyo city

Tokyo transport comprises 3 major railway systems: JR, Subway, and Private Railways.
Most of all tourist attractions in or nearby Tokyo city can be reached by these 3 railway systems.
The following figure is the railway network map in Big Tokyo area.
(View the map PDF: simplified version and complete version)