...MM.. La Linea is the "frontier town" with Gibraltar...I don't know about now but some years ago many of its residents used to commute daily to Gibraltar to work.
full name: La Linea de la Concepción. Years ago, during Franco's time, there were Smugglers and lots of smuggling going on there. But now that you can buy fake Rolexes and 'knock off' Gucci handbags all over, la Linea has probably lost its pre-eminence as a smugglers Paradise.
It's not too far from Valderrama Club de Golf (San Roque), so maybe its seedy reputation has been displaced
As stated above, this is the area adjacent to Gibraltar and I'm researching it for my next book: MacMillan Judge, Privateer. This is the one that takes place in this area, the Strait of Gibraltar and Morocco in 1815. Seems that the area was famous for smuggling more than once, lots of shall we say interesting and diabolical characters about. The stuff of great tales.
You can catch a bus to la Linea from Sevilla (Prado de San Sebastian) or ftom Cadiz. We were acquainted with a couple: He was a smuggler; she was a Baileaora back in the 60's when I was courting my wife to be. Now I am a septuagenarian and I don't get around very well or very much; but if you would like to get together for a 'mano a mano' here in Phila., send me a private message BTW I live in Mayfair (NE Philadelphia).