The best time of year to visit a European park largely depends on the specific park and its location. Generally, the spring and summer months (April to August) are the most popular times to visit parks in Europe, as the weather is typically warm and sunny, and the flora and fauna are in full bloom. During these months, visitors can enjoy outdoor activities such as picnicking, hiking, and cycling, as well as cultural events and festivals that often take place in parks. However, it's worth noting that some parks may be crowded during peak season, and visitors may have to contend with higher prices and longer wait times for popular attractions. Additionally, certain parks, such as those in mountainous regions, may be closed or difficult to access during the winter months (November to March), due to snow and ice.