The old coin is obtained in the Varrock Museum activity when cleaning Uncleaned finds. When a player returns the old coin to display case 45 (ground floor, south-west display), they are rewarded with 10 kudos. Because it has a symbol to Saradomin and writing mentioning Saranthium, it is believed to be from the ruins of Saranthium as opposed to Senntisten, which was earlier and of Zarosian religion.
A coin in very good condition with Saradominist markings. It bears the word 'Saranthium', which we have found to be the name of the city being excavated east of Varrock. The numbers on the coin would indicate that it is from the year 3804, presumably from the 3rd Age as the Godwars were coming to an end.