The Black Sea rivals the Mediterranean for history and attractions, yet it attracts only half as many tourists. Partly because many Black Sea ports can only accommodate smaller cruise ships like ours, and perhaps also because it requires a bit of an adventurous spirit to come here. This is the crossroads of Europe and Asia, the Silk Road and Spice Road, Christianity and Islam, so you never know quite what to expect. There are fewer English speakers. And cultures and cuisines may be influenced by Venetian traders, Balkan neighbors, Russian or Ottoman rulers, or regional ethnic groups. (Sochi alone has over a hundred.) Even nature defies generalization with beaches of sand or stone, pine trees and palm trees, lush green mountains and steppes.