This ancient walled city - one of the most beautiful of the entire Adriatic coast-resembles a ghost town today following the devastating series of earthquakes and tremors that shook a 100-mile swath of Yugoslavia and northern Albania on Easter Sunday.

As the toll in the earthquake rose to more than 200 killed and 1,200 injured, officials began counting the human and economic cost of Yugoslavia's greatest natural disaster since the city of Skopje was destroyed by an earthquake in 1963. There is a trail of ruined homes, wrecked harbors and collapsed roads all along the staggeringly beautiful Adriatic coastline.

United Press International quoted Yugoslav officials as reporting that 183,000 persons had been affected by the quake, which left tens of thousands homeless. More than 1,000 tourists were vacationing in seaside resorts, but officials said no foreigners were among the known dead or injured. While the bulk of the dead and injured were in Ygoslavia, Albania announced that the quake killed 35 and injured 330 along in coastline. $

Two days ago, the town of Kotor had a population of 4,000, living as they had for centuries in the twisting alleys and gentle piazzas in the shadow of the huge mountains which rise up from the fjord-like Bay of Kotor. Now there are just three residents left - and two close relative keepitnng them company.

With the exception of 70-year-old Blagoje Buchin, who is paralyzed, his brother, and one old woman , the entire population of Kotor spent Sunday and Monday night huddled around campfires trying to keep warm - terrified of going indoors in case of further tremors. There have already been two major earthquakes measuring more than seven on the Richter scale and about 200 lesser tremors.

Miraculously enough, despite an estimated 90 percent of houses being made uninhabitable, only four people were killed in the old town of Kotor during the earthquake. Ten more bodies were recovered from the surrounding suburbs.

Commented Payle Vichevic, the town engineer: "It's the villagers up in the mountains that have suffered the most. There are some villages around here which could have been totally destroyed-but it's impossible to know for sure as we still can't reach them, even by helicopter."

Vichevic said it would take at least 10 years to restore Kotor to its original condition as one of the historic cities of the Adriatic, rebuilt after a devastating quake in 1976. The port, which is one of the oldest on the coast, has been devastated.

One of the main problems facing rescue workers is the disruption of communications. Officals explained that 5,000 tents are needed to house the homeless-but only 500 have been supplied so far. A large chunk of the Adriatic Highway collapsed into the sea and supplies must be ferried to the town by boat or by helicopter.

Once the immediate emergency is over, Kotor-along with other towns along the coast-will be faced with the problem of repairing its economy, particularly the tourist trade, which is one of its main means of livelihood.