Bukit Jernih Perlis

Bukit Jernih is a pair of limestone outcrops near Bukit Ketri, and the most geologically interesting thing in Perlis that you can simply walk up to. The cliffs rise almost vertically out of flat farmland, undercut at the base by caves and hollows.

The rock is Chuping limestone, roughly 220 million years old, and it carries Triassic fossils — crinoids, nautiloids, foraminifera — visible in weathered surfaces if you know what to look for. The notches cut into the cliff bases record older sea levels, from a period several thousand years ago when the water stood much higher than it does now.

There are trails of varying difficulty, caves at the foot worth a look, and sport-climbing routes on the walls. The caves get muddy and hold bats, so wear shoes you do not mind ruining and bring a torch.

It is a well-known picnic spot locally, and quiet on weekdays.

Sources: Penang Travel Tips — Bukit Jernih, Perlis, theCrag — Bukit Jernih climbing area