Dover is a pretty splendid place in the sunshine. The castle, the cliffs and the surrounding downs all look worthy of further exploration.
The Bock casemate – part of Luxembourg’s fortifications – proved to be a good place to explore in some less desirable weather. I remember enjoying the tunnels and passages here when I visited many, many years ago, that time on the way to my first visit to Switzerland. Since then even more passages have been opened to the public.