This two-day field excursion traces nearly 2.7 billion years of Earth history along a compact transect from Karnataka's Arabian Sea coast to the Western Ghats. Beginning at St. Mary's Island, a National Geological Monument famed for its columnar-jointed rhyolitic rocks (~88–90 Ma) linked to the Late Cretaceous breakup of India and Madagascar, the route continues through Maravanthe and Murdeshwar to examine active coastal geomorphology, before crossing the Archean Dharwar Craton and the tectonically significant Kumta Suture Zone. The excursion culminates at Yana, where towering Precambrian dolomitic carbonate monoliths and cave systems showcase one of India's most spectacular tropical karst landscapes. Participants will explore volcanology, structural geology, coastal processes, and karst geomorphology, gaining a rare, integrated perspective on tectonics, magmatism, and landscape evolution along the western Indian margin.