The Ashton Trail runs up the valley of the Belalong river, a tributary of the Temburong river. It is reported to be a 4 to 6 hour walk. It was named after Peter Ashton, Conservator of Forests in Brunei in the late 1950's and early 60's, when Brunei was still British. The trail is apparently not open to the general public, but only for scientific excursions.