THE ROCK OF GIBRALTAR
426m of Jurassic limestone
Known to the ancients as one of the Pillars of Hercules, the Rock of Gibraltar dominates the Western entrance to the Mediterranean Sea.
Formed from limestone and shale deposits of the early Jurassic period, 175-200m years ago, this monolith was overturned and forced skywards by the collision of the African and Eurasian tectonic plates about 5m years ago.
Ceded in perpetuity to Great Britain in 1713, Gibraltar became an important military base for the British and it was military enthusiasts who first developed modern climbing on the Rock in the 1950s and 60s. The impressive North Front was not climbed until Martin Boysen, Mick Burke and Henry Day ascended on the Bank Holiday weekend of 31 August and 1 September 1971.
There are few regulated climbing locations on the Upper Rock but some very nice boulder problems can be found about a third of the way up the Med Steps hike (10min from the carpark). See here for the topos.
There are also about 15 bolted routes (5C to 7B+) in the King's Lines and Queen's Lines sections of the Northern Defences roughly here. The limestone is crumbly so be careful of rockfall and definitely wear a helmet.