Looking for more sites along the Horus Way in Sinai

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.

Archaeologists are hoping to use inscriptions from Luxor’s Karnak temple in Egypt as a guide to finding other ancient defensive outposts.

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

Archaeologists have determined that Pharaohs made regular journeys through Sinai in conquests against Hittites and other civilizations in the region of modern-day Israel, Palestine, 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.

Ancient Egyptians were forced to use seashells in order to fortify the mud brick used to construct the garrison, called Tell Heboua, with a wall that was 15 meters thick and 12 meters high to keep attacks at bay. The garrison lies about 9 miles out from the coast.

Tell Heboua was initially used to rid the region of Hyksos, Egyptian meaning “foreign rulers”. The Hyksos invaded the eastern Nile Delta during Egypt’s twelfth dynasty.

"When the Egyptians liberated Egypt it was a very important military action against the city here by the King Ahmose I," Abdul Maqsoud said.