This paper considers the relevance of seamounts, hydrothermal vents, and cold-water seeps for governance of the ocean in the “Areas Beyond National Jurisdiction” (ABNJ). These topographical features concentrate economically significant biotic and mineral resources, and are the site of unsustainable fishing practices. Three proposals for ABNJ governance are considered: a new legal instrument, an augmented existing regime, and national territorializing. Each is conditioned by the characteristics of seamounts and vents, whose features create governance incentives, challenges, and possibilities.