Living in Switzerland I almost have to show a photo of the alps. They are high enough to be seen everywhere, and everyone visiting Switzerland as a tourist has to pay them a visit,
Being a Londoner it is difficult to pick out a particular place to see, but St. Pauls cathedral is always a good tip. You can climb up the many stairs to reach the outside balcony with a view over London.
And back to Switzerland, why not visit Bern, its capital town. Very good on a rainy day with all the covered shopping streets and the Zytglogge Turm with its clock and moving figures.