More re Sinai forts

A military garrison of mud-brick and seashells unearthed in Egypt's Sinai desert may be key to finding a web of pharaonic-era defenses at the northeast gateway to ancient Egypt, archaeologists said on Thursday.

Archaeologists who discovered the 3,500-year-old garrison, where up to 50,000 soldiers could be posted in times of heightened tensions, say they hope inscriptions at Luxor's Karnak temple may serve as a guide to finding other outposts.

But knowing the location of the garrison at the ancient city of Tharu, in a formerly fertile area of Egypt where a branch of the Nile river once met the Mediterranean Sea, is key to understanding where to start looking.

"As we understand from the inscription at Karnak temple, the city of Tharu had two fortifications with the Nile in the middle," said Mohamad Abdul Maqsoud, who heads archaeological exploration in Egypt's Nile Delta and Sinai regions.

In their 3,000-year history, Egypt's Pharaohs often ventured across Sinai to fight Hittites and other civilizations in the area now covered by Israel, the occupied Palestinian territories, Lebanon, Jordan, Syria and Iraq.

"This city was used to protect Egypt and as a gate to the Delta. It was a post of control. If you wanted to cross the Nile, you asked for permission before you crossed the bridge," Abdul Maqsoud said.

Most Egyptian fortifications at the time were made of stone, not easily available in the Sinai. So Egyptians used seashells to strengthen the mud brick used to build the garrison, with a 15 meter thick and 12 meter high wall to discourage attack.