The largest crater we can see on the Moon from the Earth is Clavius. At 225 km wide and 35 km deep, it is a truly massive crater that would cover a large part of the UK.
Binoculars show it clearly. While any telescope will show many smaller craters within its boundaries. It is a fantastic site in any telescope, and well worth a look.
If you don,t have your own equipment, pop along to your nearest astronomical club, who will no doubt share the experience with you when you look through their telescopes.