Visakhapatnam
The Borra Caves in the Ananthagiri Hills near Araku Valley are among India's largest limestone caves, formed over a million years and studded with extraordinary stalactite and stalagmite formations that local tribal communities associate with divine origin. The illuminated chambers feel genuinely otherworldly.
Combine Borra Caves with the Araku Valley train trip — they're 30 kilometres apart and easily done in one full-day excursion.