This is the 4173rd most frequent Spanish word.
júcar
"Júcar" is the name of a river in eastern Spain.
Here, 'Júcar' refers to the proper noun, the name of a geographical feature, specifically a river in Spain.
El río Júcar es uno de los ríos más importantes de España.
The Júcar River is one of the most important rivers in Spain.
In this sentence, 'Júcar' is again used as a proper noun, indicating a specific valley associated with the Júcar River.
En el valle del Júcar, los agricultores cultivan hortalizas.
In the Júcar valley, farmers grow vegetables.
Here, 'Júcar' designates the river itself, emphasizing its role as a geographical element interacted with during travel.