Tantalizingly vague item from Daily News (Sri Lanka):
Remains of harbours used by ancient Chinese and Roman ships have been discovered in excavations carried out in the North and the East by the Archaeological Department National Heritage Minister Jagath Balasuriya said.
He was addressing officials of the five Departments under him and media at the Ministry Tuesday.
Archaeological, Archives, Museum, Galle Heritage and Janakala Centre departments come under the National Heritage Ministry.
He said kovils like Thiruketheeshwaran in Mannar and Koneshwaran in Trincomalee were identified as multi religious institutes. Steps were being taken to name them as World Heritage sites.
The Minster said funds had to be canvassed from foreign countries as well as donors for conservation work.
Poking around a bit, I did find a Roman-Sri Lankan connection mentioned in Cosmas Indicopleustes, who mentions the Greeks called the place Taprobanê. In book 11.338 he relates an interesting anecdote (this would be the time of Justinian, of course; the numbers in the quotation refer to notes in the online text put up by Roger Pearse):
 Now I must here relate what happened to one of our countrymen, a merchant called Sopatrus, who used to go thither on business, but who to our knowledge has now been dead these five and thirty years past. Once on a time he came to this island of Taprobane on business, and as it chanced a vessel from Persia put into port at the same time with himself. So the men from Adulé with whom Sopatrus was, went ashore, as did likewise the people of Persia, with whom came a person of venerable age and appearance.46 Then, as the way there was, the chief men of the place and the custom-house officers received them and brought them to the king. The king having admitted them to an audience and received their salutations, requested them to be seated. Then he asked them: In what state are your countries, and how go things with them? To this they replied, they go well. Afterwards, as the conversation proceeded, the king inquired Which of your kings is the greater and the more powerful? The elderly Persian snatching the word answered: Our king is both the more powerful and the greater and richer, and indeed is King of Kings, and whatsoever he |369 desires, that he is able to do. Sopatrus on the other hand sat mute. So the king asked: Have you, Roman,47 nothing to say? What have I to say, he rejoined, when he there has said such things? but if you wish to learn the truth you have the two kings here present. Examine each and you will see which of them is the grander and the more powerful. The king on hearing this was amazed at his words and asked, How say you that I have both the kings here? You have, replied Sopatrus, the money 48 of both —- the nomisma 49 of the one, and the drachma, that is, the miliarision 50 of the other. Examine the image of each, and you will see the truth. The king thought well of the suggestion, and, nodding his consent, ordered both the coins to be produced. Now the Roman coin had a right good ring, was of bright metal and finely shaped, for pieces of this kind are picked for export to the island. But the miliarision, to say it in one word, was of silver, and not to be compared with the gold coin. So the king after he had turned them this way and that, and had attentively examined both, highly commended the nomisma, saying that the Romans were certainly a splendid, powerful, and |370 sagacious people.51 So he ordered great honour to be paid to Sopatrus, causing him to be mounted on an elephant, and conducted round the city with drums beating and high state. These circumstances were told us by Sopatrus himself and his companions, who had accompanied him to that island from Adule; and as they told the story, the Persian was deeply chagrined at what had occurred.
There’s also a bit on Taprobane in Strabo 15.14 ff … here’s the incipit of that via Lacus Curtius:
14 As for Taprobanê,15 it is said to be an island situated in the high sea within a seven days’ sail towards the south from the most southerly parts of India, the land of the Coniaci; that it extends in length about eight thousand stadia16 in the direction of Aethiopia, and that it also has elephants. Such are the statements of Eratosthenes; but my own description will be specially characterised by the addition of the statements of the other writers, wherever they add any accurate information.
15 Onesicritus, for example, says of Taprobanê that it is “five thousand stadia in size,” without distinguishing its length or breadth; and that it is a twenty days’ voyage distant from the mainland, but p23that it is a difficult voyage for ships that are poorly furnished with sails and are constructed without belly-ribs on both sides;17 and that there are also other islands between Taprobanê and India, though Taprobanê is farthest south; and that amphibious monsters are to be found round it, some of which are like kine, others like horses, and others like other land-animals.
A book on the subject might be worth tracking down … here’s the publisher’s description of D.P.M. Weerakkody, Taprobanê: Ancient Sri Lanka as Known by Greeks and Romans:
The author brings together the references to Sri Lanka (the island of Taprobanê in Greek and Latin texts) for the purpose of examining their value as sources for the study of ancient Sri Lanka. One of the main reasons for Sri Lanka to maintain political, religious and commercial relationships with the external world was its role as a great emporium in the long distance maritime trade, a result of its central position in the Indian Ocean, its numerous bays and harbours facilitating both sea-borne and inland trade and its holdings of high export value goods such as precious stones, textiles and spices. Any study of this commerce has to be based on literary and epigraphical sources on the one hand and archaeological evidence on the other. The range of the volume is vast and includes not only a critical assessment of all the notices by classical writers on Taprobanê (the author provides an up to date analysis), but also a chapter on Roman coins found in Sri Lanka and a chapter on alleged classical references in the interlinear inscriptions from Sri Lanka, which questions their genuineness. Through this book we have a recourse to a work of reference for any study on ancient Sri Lanka and its important position in the world of the Indian Ocean.