Passage: As Colombo possesses a natural harbour, it was known to Indian, Greek, Persian, Roman, Arab, and Chinese traders over 2,000 years ago. Traveller Ibn Battuta who visited the island in the 14th century, referred to it as Kalanpu. Arabs, whose prime interests were trade, began to settle in Colombo around the 8th century AD mostly because the port helped their business by the way of controlling much of the trade between the Sinhalese kingdoms and the outside world. Their descendants now comprise the local Sri Lankan Moor community.

Question: How many years ago was the natural harbour known to?
over 2,000