There are 23 national parks in Poland. They protect the charm and natural uniqueness of areas by the sea and lakes, and also the invaluable primaeval forests, the river estuaries unlike anything else in Europe, the chalk cliffs and limestone caves, and the mountains. Eight of the parks - the Slowinski, Bialowieza, Kampinos, Babia Góra, Karkonosze, Tatra, Bieszczady, and Polesie - have been entered on the UNESCO list of World Biosphere Reserves. The parks are all accessible to tourists, and visiting is possible thanks to 2,500 km of signposted tracks and trails for walkers, riders, cyclists, and canoeists. A symbolic entrance fee is charged, and the regulations are quite liberal: you must stay on the path and camp only in the designated areas; you mustn't leave litter; and hunting is prohibited, but you can watch the wildlife with a camera. Poland has over a hundred natural landscape parks and over a thousand nature reserves. Particular attractions are the natural wildlife reserves: in Bialowieza and Miedzyzdroje, you can see bison, boar and deer in their natural environment, and in Popielno and Kadzidlowo in Masuria there are Polish ponies, beavers and wolves.