On the second day of her trip to Gibraltar Emma Pinch joins the the Territorial Army's 35 Signal Regiment as they leave the sunshine behind and venture into the island's network of underground tunnels...
Gibraltar's unique network of tunnels provides a perfect practice ground for some of the terrain the members of 35 Signal Regiment could come up against.
The Rock's dense warren of tunnels runs for 32 miles - an impressive distance when you consider the island itself is only three miles long and one mile wide.
The forerunners of the Royal Engineers began work excavating the tunnels during the Great Siege of Gibraltar, and between 1939 to 1944 they were extended to include some big enough to drive a truck through, and to house a veritable town of command stations, stores and barracks.
The major tunnels bear street names named after the person who excavated them.
Major Chris Lewis, the officer in command during the 35 Signal Regiment's trip to Gibraltar, said the army was once again finding a vital use for the Rock's tunnel system.
"There is a huge tunnel system in Afghanistan and in much of the Middle East there are tunnel networks," he said.
"The US has had great difficulty dealing with them. If we had to defend the Tube system in London we would also need to use these tactics.
"The Gibraltar Regiment is currently writing a doctrine on how you fight in tunnels which will be followed throughout the army, and Gibraltar's tunnels will be more widely used for practice."
Earlier this year the Gurkhas came to the Rock to practise tunnel tactics and the Signallers were following the same procedures.
The scenario constructed was one where terrorists had hidden in the tunnels and 20 soldiers were patrolling down them with rifles at the ready.
"If they are fired on it is up to the patrol leader to determine how many there are and decide whether to pull back or go forward," added Major Lewis.
Their tactic is to usually only go into battle with combatants if the military force outnumbers the enemy by the ratio of three to two.
Mayur Patel, aged 25, was the officer in command of the patrol and as such the person charged with making those decisions.
In May, Mr Patel, an information and technology specialist from Shrewsbury, completed his three-week Queen's Commission course which all prospective TA officers must undertake.
"This exercise has been the highlight so far for me," he said. "There's nowhere else you would get the opportunity to do something like this and if I came to Gibraltar on holiday I would never do it.
"I joined the TA in 2003 when I came out of university and I was struggling between jobs. I had friends in the army so I thought I would try it out.
"I did think about joining the regular army but I think I've got the best of both worlds now."