Actually this site fails to mention that this is not a reconstruction but a repair. Two of the stones collapsed, I believe, due to tourists or something(I'll find a source in a moment) and they merely hoisted the stones back into their original positions.
Also the website itself is a conspiracy/alien website. Here is the homepage.
Cosmic Conspiracies
EDIT: Here is a source on the disrepair of Stonehenge:
STONEHENGE ANCIENT DRUID STONE HENGE MONUMENT | AMESBURY, SALISBURY, WILTSHIRE.
"The stones we see today represent Stonehenge in ruin. Many of the original stones have fallen or been removed by previous generations for home construction or road repair. There has been serious damage to some of the smaller bluestones resulting from close visitor contact (prohibited since 1978) and the prehistoric carvings on the larger sarsen stones show signs of significant wear."