Final answer:
The capital city on the Guaire River, near the Caribbean Sea and separated by El Avila National Park, is Caracas, the capital of Venezuela.
Step-by-step explanation:
The capital city located on the Guaire River, approximately 15km from the Caribbean Sea and separated from the coast by El Avila National Park, is Caracas.
Caracas is the capital of Venezuela and is nestled in a valley away from the coast. The city's proximity to the sea and various geographical elements, such as the Guiana Highlands to the southeast and Lake Maracaibo to the northwest, contribute to its unique setting and climate.
Furthermore, the surrounding regions of Venezuela, from the Guiana Highlands with the impressive Angel Falls to the grassland region of the Llanos, showcase the country's rich natural diversity and wealth of natural resources like oil.