VIRGINIA BEACH — Patches of dull, greyish-black sand cover the beach near the water’s edge at 23rd Street. The dark sections stand out in contrast to the bright tan grains closer to the Boardwalk.

This quiet stretch of black and gray volcanic sand sits on the north coast of Bali, just a short distance south of Singaraja, the capital city of the Buleleng regency. A highlight of this laid ...