In the 19th and most of the 20th century large numbers of foreign tourists came, especially British, showing interest in the agriculture of the islands. With the world wars, this sector weakened, but the start of the second half of the century brought new forms of tourism. Due to its warm climate, the first emphasis was on Puerto de la Cruz, and for all the attractions that the Valle de la Orotava offered, and following the promotion sun and beaches, around 1980 the tourist boom was born in south Tenerife. The emphasis was on cities like Arona or Adeje, shifting to tourist centres like Los Cristianos or Playa de Las Americas, which now house 65 percent of the hotels on the island. Tenerife receives more than 5 million tourists every year; of the Сanary islands Tenerife is the most popular. However, this data also reflects the large quantity of resources that tourism consumes (space, energy, water etc.)