Ancient Greek colony founded 5th century BC! UNESCO World Heritage site since 2013. Where Vladimir the Great was baptized in 988, bringing Christianity to Russia. Free entry to ruins.

Secret Soviet submarine base built inside mountain! Could shelter 7 submarines from nuclear attack. Now museum. One of most unique Cold War sites in the world.

For heroic defenses: 349 days in Crimean War (1854-55) and 250 days in WWII (1941-42). Both times nearly destroyed but defended fiercely.

Fly to Simferopol (SIP), then bus 1.5-2h to Sevastopol. Or train from Russian mainland via Crimean Bridge. No direct flights.