Cities sap your money when you're travelling. Accommodation, transport, food - the price of these necessities spirals once you reach the metropolises of the world. The bigger and more renowned the city, the more expensive it tends to be. Yet some places buck this trend. Sprawling urban conurbations on continents such as South East Asia; densely populated gateways to natural wonders, such as African plains or Himalayan peaks; such places yield all the excitement and opportunities of a city break without breaking the bank.