Tourism is big business. It is one of the world's largest industries and in many regions the single largest source of investment and employment. While it does not have the same 'smokestack' image as the manufacturing industry, it is by no means environmentally benign, generating significant levels of pollution and consuming considerable amounts of natural resources. Europe is the world’s favourite tourist destination and so faces considerable challenges in making its tourist industry more environmentally friendly. One of the biggest beneficiaries of a more sustainable tourism industry will be the industry itself — fewer people will want to visit a region where mass tourism has blighted the countryside and polluted the beaches.So as tourism industry is expanding day by day.We people from 21th century have basic concept of tourism.In todays world Tourism is one of the great business and more than 10 million people are directly depended on this business.Most of the countries of Europe their main business is Tourism.