Gluggafoss

Gluggafoss (“Window Waterfall”), also called Merkjárfoss, is a multi-tiered cascade on the Merkjá river in South Iceland. What makes it special is a natural cave passage behind the lower curtain — visitors can step through a rocky “window” and see the water thundering past from the inside.

The waterfall is impressively large for such a little-known site, and the mossy canyon walls give it a secretive, intimate character quite different from the wide-open grandeur of nearby Skógafoss. The scramble up the canyon beside the falls also rewards with views over the surrounding farmland.

Access is via a short unpaved track off Route 261 (Merkjarvegur). A dirt parking area sits at the base; from there it is a gentle 10-minute walk along the river bank. The cave passage is accessible when water levels are not too high — best in late summer.