Johor Bahru is the state capital of the state of Johor and the second largest metropolitan area in Malaysia. Most tourists don't stop here and just pass through the city on their way to or out of Singapore. JB is a major local transportation hub however. Since it is just across the causeway from Singapore, some travellers use it as a hub to visit Singapore from here (lower accommodation prices) or to board the train, bus or airplane.
Singapore is an island nation located at the southern tip of the Malay Peninsula. At 704.0 sqkm (272 square miles), it is one of the few city-states in the world and the smallest country in Southeast Asia.