Cities with Tubes (underground trains)

I for one love the flexibility and ease of travelling around a large city on the tube. In my home city of London the tube makes zipping around the sights and attractions quick and easy and somewhat affordable if you buy the correct ticket. In any city which has an underground transit system you will definitely see the advantages of a tube if you are used to travelling across town on a bus in the middle of rush hour. You could argue that tubes can be just as uncomfortable and sweaty in rush hour as buses as you will get packed on, but some places such as Tokyo have employed people to make sure every last person is squeezed into the carriage by using force if necessary. In Hong Kong however, the journey’s can be much more pleasant as the carriages are air conditioned so even on the snuggest journey you can be pretty confident that your armpits will remain dry. This is a rarity because many of the underground networks are very old and an effective air conditioning system would be expensive to put in place.

I found a wiki site which lists all the cities in the world which have an underground transit system. This is a good reference if you would like to visit a city knowing that travel around it is easy.

http://en.wikipedia.org/wiki/List_of_metro_systems#A

Another good article I found shows arguably the best underground systems in the world.

http://www.virgin-vacations.com/site_vv/11-top-underground-transit-systems-in-the-world.asp