Lizards are distributed throughout the world, and as the San Diego Zoo notes, most of them live on the ground. Other common lizard dwelling places are underground burrows (especially in deserts), under rocks, marshy bogs and in trees.
Lizards are cold-blooded animals, meaning they do not have a high enough metabolism to regulate their own body temperatures. This means that globally distribution is higher in the tropics, sparser in temperate regions and entirely nonexistent at the poles. Lizards rely on the ambient temperature of the regions they inhabit to provide them with sufficient energy to remain active. Snowy mountain peaks, icebergs and even temperate regions in the winter are all exceedingly inhospitable places for lizards to live.
On the other hand, deserts, which are primarily inhospitable to most forms of life, provide lizards with all the heat they could ever need. The desert monitor lizard's range includes the Sahara, and the only two venomous lizards, the Gila and the horned toad, both make the deserts of the southwest United States their homes.
Of the familiar lizard families, marine iguanas are great swimmers. Chameleons are all tree dwellers, along with anoles and skinks. The enormous monitor lizards are a ground-dwelling group.