La Línea (or more properly La Línea de la Concepción) is a city in the Cadiz province of southwestern Spain, just over the border from Gibraltar.
It doesn't have much to recommend it as a tourist destination in itself, but as you will have to at least pass through it if you're entering Gibraltar by land, it's many atmospheric bars and restaurants might warrant a visit.
As you can walk from the centre of La Línea to the centre of Gibraltar in less than half an hour, it also provides alternatives for accommodation if you find yourself balking at the Gibraltan prices.
There is a small tourist office on the Av Principe de Asturias, just opposite the Gibraltar border, or a bigger one towards the town centre (another 5 minutes walk as you continue walking directly away from the border down Av 20 de Abril), where you can get maps and lists of accommodation.
Meson La Serrana, 44 Calle del Sol, La Linea de la Concepcion, 11300, ☎ 956178179. Lunes - Viernes:8:00h - 16:000h y 20:00h -24:00h. Abrimos sabados y domingos. ( de 12:00h- 16:30 y 20:00h-01:00h).. Reasonably priced tapas in the town centre, try the goats cheese canapes and the secreto iberico.edit
Tornasol, Calle del Sol 66 (At the junction of Calle del Sol and Calle López de Ayala). 10:00-00:00. A very friendly and relaxed bar run by two English-speaking guys (one of whom is an opera singer) with free wifi and computers providing internet access. They have a good range of drinks and food, and claim their hamburger has the pedigree of being the direct descendant of the second ever to appear in Spain!(36.16274687119144,-5.352530479431152)edit
Betty Blues, Calle López de Ayala (On corner of Calle Sol and Calle López de Ayala, next to Tornasol). A bar with pool and poker tables popular with the Brits working in Gibraltar. The bar staff all speak English.edit