The castle was ruined by the end of the 15th century, and sat at the bottom of Coinagehall Street, where the bowling green and Grylls Monument are now located.

The only contemporary source for the castle whilst it was in use is the Caption of Seizin of the Duchy of Cornwall, prepared for The Black Prince in 1337.

[4] The location of the site, overlooking the river valley, which at the time may have been accessible from the sea, has also led to suggestions that it was more defensive in nature.

Another fifty years later, John Leland remarked:"Hailestoun, alias Helles, stondith on an hill, a good market tonn, having a mair and privileges; and coinage twis a yere for tynne blokkes.

[4] The former site of the castle is now the location of a bowling green and the Grylls Monument, at the bottom of Coinagehall Street.