Simplify the following text for a Grade 6 native English-speaking person.
Original: It is linked by the narrow ( about 4 km ) Strait of Kerch to the Black Sea to the south and is bounded on the north by Ukraine mainland , on the east by Russia , and on the west by the Crimean Peninsula .
Simplified: It is bounded on the north by Ukraine , on the east by Russia and on the west by the Crimean peninsula .