Rural Romania reminds me of Gen. Francisco Franco's Spain in the early 1960s, a throwback to an earlier era, just before massive social and economic changes propelled Spain into the modern world. Come back to Romania in 10 years and all this may be gone, too.

Many things tempt visitors to Romania, including prices far lower than Western Europe's, good food and drinkable local wines, the mountain villages of the Carpathians, and in Transylvania, of course, the legend of Dracula. Yet I came to Romania to unearth traces of the Roman Empire, in a field-trip vacation organized by the Earthwatch Institute. This ecologically minded organization sponsors scientific studies all over the planet. Volunteers pay to join an expedition for a working vacation under the guidance of a scientist or expert in a particular field. I was attracted to the Earthwatch-funded archaeological dig of the Roman frontier fort at Halmyris.

Emperor Trajan's restored monument to his victory over Dacian barbarians at Adamclisi.

After the Roman Empire converted to Christianity, a church was built within the walls of the fort. The remains of two early Christian martyrs, Saint Epictetus and Saint Astion, were buried in a crypt beneath the basilica.

My fellow Earthwatch volunteers and I spent two weeks excavating the church, digging through the ancient fill dirt and discovering animal and human bones, and numerous pottery shards and amphorae handles, as well as the occasional Roman coin or nail.

A Roman soldier battles native Dacians in this metope, or carved panel, at Adamclisi.

Zahariade's excavations have revealed that the fort was attacked and damaged several times in its 600-year existence, but each time it was rebuilt and strengthened. By the late 6th century, however, the Byzantine emperors in Constantinople could no longer hold back the invading tribes pressing on the empire's Danube border, and Halmyris was finally abandoned to its fate.

When we weren't digging, we relaxed in our communist-era hotel not far from the fort, in the village of Murighiol, and I quickly learned to expect the unexpected in this establishment. We always got up early to do the archaeological excavations before the sun got too hot, so at 6 o'clock one morning I went downstairs to the hotel lobby. No guests or staff members were evident anywhere, and the front doors had been left wide open. I was not alone, however. A large horse and her colt ambled in the open doors, crossed the carpeted floor, and stood by the deserted reception desk, switching their tails and serenely surveying the room. Horses in the lobby? I ran back to my room to get my camera, laughing all the way.

Earthwatch volunteer Bob Miurhead of Australia helps excavate the ruins at Halmyris.

The restored monument is a cylindrical structure 131 feet in diameter and originally the same height, topped with a 49-foot statue wearing the armor of a Roman soldier. Around the cylinder are carved metopes (bas-relief panels) depicting scenes from the battle, superb examples of provincial art.

Next to the monument is the Roman equivalent of the Vietnam War Memorial in Washington, D.C., a stone wall on which were inscribed the names of some 3,800 Roman legionaries who fell in the struggle.

Another volunteer, Bruce Clubb of Alexandria, Va., stands atop a wall at Halmyris.

We walked to the other side of the hilltop site, and there I saw two enormous trenches, dug to the base of massive Roman walls that were at least 30 feet high. The nondescript hill we were standing on contained nothing less than the ruins of the main naval base for the Romans' Danube and Black Sea fleet, Noviodunum. Below the grass where the sheep grazed were several acres of hidden ruins built on a monumental scale — huge stone buildings, walls, gates and catapult towers designed to fend off the barbarian onslaught from the north.

A memorial wall at Adamclisi commemorates Roman troops who died there. Panels carved with their names were removed to a museum.