The never-ending queues of Spanish traffic and border delays have also been a thorn in the side for politicians in both Madrid and London.
The neighbouring Spanish have long demanded the territory be handed back to them, ever since it was signed over to the British in 1713 under the Treaty of Utrecht.
According to the last referendum, most of Gibraltar's 30,000 residents are strongly in favour of maintaining their links with Britain - and equally opposed to Spain's consistent claims for ownership.
A deal signed between the UK and Spain in April achieved a compromise on the administrative status of the disputed territory, but the row over sovereignty rumbles on.
Breaking down barriers
Under the latest deal, the barriers to European Union (EU) legislation on a number of issues have been broken down, with Gibraltar identity cards being accepted throughout the EU for the first time.
For years Spain has been blocking EU directives because it does not recognise the Gibraltar government as a competent authority.
The never-ending queues of Spanish traffic and border delays have also been a thorn in the side for politicians in both Madrid and London.
Under the April agreement, a small unit in the Foreign Office in London now acts as a "post box" to channel communications between Gibraltar and European governments.
Paths of history
People have been travelling to and from Gibraltar for centuries, although the Gibraltar government has always strongly rejected allegations from Spain that it is a smuggler's haven.
Home to a huge 1300ft chunk of limestone, which provides a residence for several hundred Barbary apes, the territory is also frequently referred to as The Rock.
Behind a strong facade can also be found 32 miles of tunnels, mainly forged by the British in their attempts to stay put.
Naval base
Gibraltar remained Spanish until early in the 18th century, when it was captured by the British, and formally ceded to the Empire.
It is now a British air and naval base at one of the world's strategic cross-roads.
There have been a number of Spanish attempts to retake Gibraltar, which is connected to the mainland by a mile-long peninsula.
In 1779, Spain's "Great Siege" lasted for four years, causing great destruction to Gibraltar and its fortifications.
In 1963, the question of Gibraltar's status came before the United Nations Special Committee on Decolonisation, and Spain seized the opportunity to revive her claim for the reversion of the Rock to Spanish sovereignty.
Spain increased border restrictions with Gibraltar and eventually closed the frontier and all other means of direct communication with the mainland in 1969.
After 16 years of isolation from mainland Spain, the frontier gates were reopened, but relations are far from cordial.