Here is the link given- apparently there is a long battle over where the border should actually be, and that some land was wrongly taken for the airport.
''"In 1909 Britain decided to reduce the number of sentries and built a fence 7 feet (2.1 m) high,[5] however there was suspicion about the motives for doing so.[6] The line of this fence has become the de facto border. Spain claims that, by building the fence where it did, the United Kingdom annexed 106 of the original 156 hectares of neutral ground. In this location Gibraltar International Airport was built.[citation needed]" en.wikipedia.org/wiki/Gibraltar%E2%80%93Spain_border''
Army horses loose on London streets
The Republic of Ireland and their tensions with migrants.