Tourism helped preservation of historical sites for their broader economic usefulness. Famous monuments form the backbone of local economy and hence authorities are forced to protect them fearing the loss of source of revenue and employment. Locals who reap economic benefits of tourism, also work for the preservation. Preservation of historical sites require expensive technologies, so their conservation is not the top priority of governments.
Money earned from tourists is the most important source of finance for the conservation of historical sites. Pyramids of Egypt is preserved by the best preserving techniques due to the money provided by tourism. Same is the case of archaeological complexes of Greco-Roman world and ancient sites of America which are extremely well preserved almost entirely due to their attractiveness to tourists.
In India too, several historical sites are protected for their tourism potential and by the money provided by tourists. Taj Mahal, one of the best preserved monuments in the world has been so well preserved for its 'attractiveness' to the world tourists and the money earned from them. Khajuraho, a neglected sleepy village with ancient monuments became a 'World Heritage Site' due to tourism which promoted the place to international tourists.
Heritage resort concept in which old and ruined havelis and mahals were converted to resorts and hotels, is another example of tourism being a 'tool for conservation'.