Objective: Taq-e Bostan Boulevard in Kermanshah, as the longest forest boulevard in Iran, represents a unique integration of nature, history, and urban life. This study aimed to explain the relationship between the perceptual richness of biophilic spaces and citizens' satisfaction within this boulevard. The term "biophilic spaces" refers to natural-historical contexts possessing biophilic elements and potentials, not necessarily spaces where all principles of biophilic design have been fully realized.

Methods: This applied research employed a descriptive-survey method with a mixed quantitative-qualitative approach. Due to the fluid population, 600 individuals were selected through convenience sampling. The instrument was a researcher-made questionnaire comprising 26 items across six factors. Validity was confirmed by five experts, and reliability was calculated using Cronbach's alpha (0.81). Data were analyzed using Pearson correlation and multiple regression.

Results: All six factors demonstrated positive and significant correlations with satisfaction (0.74 to 0.85). Regression analysis revealed that the six factors explained 73% of the variance in satisfaction. The biophilic-natural factor (β = 0.32) was the strongest predictor. Socio-cultural and semantic-psychological factors showed no direct effects, suggesting indirect influence. All three hypotheses were confirmed.

Conclusion: Taq-e Bostan Boulevard holds substantial potential for enhancing satisfaction through its historical-natural integration and assets such as water features and ancient trees. Strengthening natural and sensory qualities is key to the success of linear urban spaces. Improving nighttime lighting, designing nature-compatible furniture, increasing native plant diversity, and enhancing ordered visual complexity are the most important recommended strategies.