A small glass tower channeling light into an underground chamber
was unveiled as a memorial to victims of the Madrid train bombings,
meters away from where the blasts killed 191 people exactly three
years ago on Sunday.

King Juan Carlos and Queen Sofia inaugurated the memorial --
a glittering cylinder of glass brick -- less than a month after
29 suspects went on trial in the attack that ripped apart four
rush-hour trains approaching Madrid's Atocha railway station.
Around 1,800 people were injured by 10 bombs, which had been
stuffed into sports bags and set off by mobile phones. One woman
remains in a coma and hundreds others are still plagued by medical
and psychological problems.
On a sunny spring day, relatives of victims and survivors bowed
their heads in silence as the king laid a wreath at the foot of
the 11-meter (36 ft) tower -- its height a reference to the date
Spain suffered its worst peace-time attack.
The tower's architects -- five friends working on their first
commission -- said the design's main ingredient was light.
Sunshine hitting the column of 15,000 glass bricks focuses light
into an empty, blue chamber below a busy highway, which the public
can access via Atocha station.
From below, visitors can peer skywards to read hundreds of messages
of condolence and support wrapped around the inside of the cylinder.
"When the sunlight completely fills the chamber, it's like
an explosion of light. It's a calm environment, a place of reflection,"
one of the architects, Esau Acosta, from firm Estudio FAM told
Reuters.
Three days after the bombs, Spain held general elections and
voted out the conservative Popular Party (PP), a close U.S. ally,
putting in its place a Socialist government that quickly fulfilled
a pledge to pull Spanish troops out of Iraq.
The trial of those accused of carrying out the attacks will hear
from more than 600 witnesses and 100 experts before a panel of
three judges gives its verdict, probably in early autumn.
Separate commemorations were held at two other stations hit by
blasts on Sunday.