Galle has a natural harbour that has been used for over 2000 years, and became prominent after the 12th century. The great Chinese Admiral Zheng He commemorated his visit by leaving a trilingual inscription in 1411. The three languages were Chinese, Tamil, and Arabic, implying a cosmopolitan trading community. Among the Asian ports of the United Dutch East India Company, Galle was second only to Batavia (present day Jakarta). Galle was probably the most important port in the country until an artificial harbour was built in Colombo in 1873.
Galle harbour has many heritage sites, some dating back well before the arrival of Europeans in the 16th century. Several stone anchors of Indo-Arabian pattern have been discovered. An anchor weighing almost one ton is probably from Oman. Another anchor has been found with Mediterranean patterns, similar to those used in Roman times. A celadon bowl of the Southern Song dynasty is one of few relics remaining from the early trade with China.