a landmark: a famous building, object or landscape item (e.g. a hill, a rock, a gorge etc.) that you can see and recognize easily

Here are some of them from London:

GLOSSARY

a gherkin – a small green pickled cucumber

a dome – a roof shaped like the top half of a ball (/sphere)

an abbey – a lage church with its buildings where monks or nins live or lived

a column – a tall thick post

headquarters – a building where a company or organization has its central and most important offices

a tube – a long hllow object or a long narrow container (e.g. for mustard, ketchup, mayo etc.)

The Tube – Lonon’s underground (= metro) network