Museo Arqueológico Nacional. I have a series about the museum's collections coming up on the Black Gate blog, but in the meantime here's an interesting reconstructed grave of a Celtiberian warrior.
The Celtiberians were a mix of Celtic and native Iberian cultures. This grave dates to the 3rd century BC and was found near Zaragoza. It's a cist marked by a stela and contains an iron sword with silver damascening, the remains of a baton, a spear, tweezers, and a razor. You have to look good in the afterlife! There was also a spindle whorl and a clay ball of uncertain use. A pot contained the warriors cremated remains.