Where is the landmark of Wales?

Which one? There are many! Are you asking what is Wales's most famous landmark? If the latter then it would probably be Mount Snowdon in the North, the second highest mountain in the British Isles at 1,085 metres. It is frequently cloud-topped and can be dangerous to climb; some climbing routes are easier than others but many people have lost their lives trying to get to the summit in bad weather conditions and when not properly equipped. There is a narrow-gauge steam railway built in Victorian times that takes visitors to the top of Snowdon and back, which is the safest way to get to the summit, where there is a restaurant and visitor's centre.