Final answer:
The capital and largest city of Costa Rica is San Jose, located in the Central Valley with the prominent La Sabana Park, reflecting the nation's culture as a primate city.
Step-by-step explanation:
The capital and largest city in Costa Rica, which sits in the Central Valley and is home to La Sabana Metropolitan Park (founded by Monseñor Amon), is San Jose. This vibrant city is not only the country's political center but also a primate city, meaning that it holds a significant percentage of the country's population. San Jose is known both for being the administrative hub of Costa Rica and a cultural beacon that reflects the national identity. The city's strategic location in the fertile Central Valley allows it to be a focal point for economic activity within the country, which is known for its democratic and peaceful stance, lacking a military and often being referred to as the 'Switzerland of Central America.'