Near-Earth asteroid 2012 DA14 (hereafter DA14) made its closest approach to the Earth on February 15th, 2013, when it passed at a distance of 27,700 km from the Earth’s surface. It was the first time an asteroid of moderate size 45 m estimated before the approach) was predicted to come that close to the Earth becoming bright enough to permit a detailed study from ground-based telescopes. With the aim of collecting the most varied and useful information within our grasp, we designed and carried out an observational campaign that involved five ground-based telescopes with very different characteristics. Visible colors and spectra were obtained from the 10.4m Gran Telescopio Canarias and the 2.2m CAHA telescope; near-infrared colors were obtained from the 3.6m Telescopio Nazionale Galileo; time-series photometry were obtained using the f/3 0.77m telescope in La Hita Observatory and the f/8 1.5m telescope in Sierra Nevada Observatory (all telescopes placed in Spain). The analysis of the data showed that this NEA can be classified as an L-type, with an estimated geometric albedo in the visible pv= 0.44 ± 0.20. L-type asteroids are uncommon, and most of them display unusual characteristics, which indicate that their surfaces could be covered by a mixture of high- and low-albedo particles similar to what is observed for some carbonaceous chondrites (CV3 and CO3). The object is very elongated, and its equivalent diameter is 18 m. This is less than a half of the a priori estimation, which suggests that close approaches with objects such as DA14 are several times more frequent than initially estimated before this work (once every 40 years). Using photometric time series pre- and post-encounter, we show that the object probably experienced a spin-up due to the gravitational forces of the Earth decreasing the rotational period from 9.8 ± 0.1 hr. to 8.95 ± 0.08 hr.