Final answer:
Basseterre is the capital and largest city of Saint Kitts and Nevis, located on the southwestern coast of Saint Kitts Island, and serves as an important hub for transportation and the economy.
Step-by-step explanation:
The capital and largest city of Saint Kitts and Nevis is Basseterre, which is situated on the southwestern coast of Saint Kitts Island. Basseterre plays a crucial role in the country's economy and cultural identity, and it is the main gateway for both sea transportation and international travel into the nation. As an essential hub, the city provides vital connections for trade and tourism.
The capital city is crucial to the nation's infrastructure, supporting transportation systems such as highways and railroads, which are particularly important for a country with such significant coastal access and are more challenging to construct in mountainous or highland regions.