Also known as the Portuguese Fort, Qal'at Al-Bahrain is the
country's main archaeological site. Beginning in the 1950s,
excavations revealed the fort to be sitting on a tell, a
hill formed from the rubble of previous cities. In all,
seven layers of occupation were discovered, the earliest
dating from 2800 BC.
The fort, located on the north coast, was built in the 14th
century, but excavations in the area reveal it to be the
site of settlements dating back to the Dilmun era, or around
3000 BC.
In the early 1500s, the Portuguese saw Bahrain as a key
point to protect their trade routes between India, Africa
and Europe. They invaded the island and set up military base
at the Bahrain Fort. They strengthened the perimeter and
erected new stone towers. The fort is still sometimes
referred to as the Portuguese Fort.
The site was named a WHS in 2005 because it is seen as a
'meeting point of cultures'. Also, it was the capital of one
of the most important ancient civilizations of the region
the Dilmun civilization.
http://worldheritage.heindorffhus.dk/frame-BahrainQalatAlBahrain.htm
http://perso.wanadoo.fr/breiz.positive/images%20bahrain%20bahrain.htm
http://www.travel-images.com/bahrain.html