Gibraltar is a curious corner of the United Kingdom, looming off the coast of Spain. Resolutely British, 'the Rock' as it is known, is an amazing amalgam of influences and cultural associations, with residents speaking both English and Spanish, signposts in English and curiosities including red post boxes and bobbies on the beat.
The main site is the Rock itself, an enormous limestone ridge rising abruptly from the sea and protecting the access to the Mediterranean. There are spectacular views from the top, which is also home to a troop of Barbary macaques. You'll also want to explore the town, its military history and installations to understand the strategic importance of the place.
Other options include diving and dolphin trips. And, be sure to leave time for some tax-free shopping, with everything from computers to jewellery to lacework and silk available at bargain-basement prices.