Besides the Dilmun antiquities, the museum has displays devoted to pearl fishing and local art and clothes. Particularly interesting are those devoted to women's clothing, showing the sumptuous traditional Bahraini marriage dress and the scarcely less magnificent clothes worn in the old days by unmarried women. Of course, in the street, Bahraini women to this day continue to be shrouded in black veils, but at home they look very different.

A 15- minute taxi ride from any of the big hotels along King Faisal Boulevard will take the Dilmun enthusiast to the site of Mr. Bibby's first great find: Qala'at al-Bahrain, known in English as the Portugese fort.

Only the tumbled-down walls remain, though inside you can see the remnants of the palm-leaf encampment Mr. Bibby and his Danish companions built there in 1957. the last vestiges of what the acheologists dubbed the ''Carlsberg Culture'' after the Danish beer they drank.

But below the fort's southern walls lie remaining bits of the walls of the Dilmun-age ''palace'' they found, the first evidence there was a thriving civilization on the island 4,000 years ago. Here were discovered the famous Dilmun seals and weights, which link the island with ancient Ur and the Indus Valley, confirming its importance as a trading center. But here Mr. Bibby also found astonishing evidence of a direct religious link between the inhabitants of ancient Dilmun in the third millennium B.C. and the much older legend of Gilgamesh's unfortunate encounter with the serpent - ritually buried rows of pots, each containing a snake's skeleton and a pearl.

The pearl Mr. Bibby identifies with the Flower of Immortality, recalling how in ancient Egypt Cleopatra drank an elixir of pearls dissolved in wine. ''Here we have clear proof that the legend of Gilgamesh was still a living and integral part of the religion of Bahrain at the time the palace was built and inhabited,'' he writes.

Today, visitors can scramble into the pit and walk along the streets of ancient Dilmun, admire the great stone doorway of the palace, clamber through its rooms and recall how its inhabitants also commemorated man's fall centuries before Genesis was written.

A few miles west of the fort lies Mr. Bibby's second major site, the Barbar Temple. After their first exploration, Mr. Bibby and his companions re-covered the temple with sand to stop theft. But last year the Bahrain Government re-excavated it, building a permanent site with concrete walkways and viewing points for visitors.