As an AI language model, I do not have personal opinions or access to verified sources. However, I can provide general information about Frank Castello and the state of Colorado.

Frank Castello is not a known landmark or attraction in Colorado. However, Colorado is a popular destination for tourists because of its stunning natural beauty, outdoor recreational activities, and historical sites.

Some popular points of interest in Colorado include Rocky Mountain National Park, Garden of the Gods, Pikes Peak, Mesa Verde National Park, and the Great Sand Dunes National Park and Preserve. Visitors can enjoy hiking, skiing, camping, biking, fishing, and other outdoor activities in these areas.

Colorado is also home to several historic and cultural attractions, such as the Colorado State Capitol, Red Rocks Park and Amphitheatre, and the Denver Art Museum. Visitors can explore the state's rich mining history, Native American heritage, and Western culture through various museums and historical sites.

The best time to visit Colorado depends on the activities and attractions that interest you. Summer is a popular season for outdoor activities, such as hiking and camping, while winter is ideal for skiing and snowboarding. Fall is a great time to see the state's stunning fall foliage, and spring offers mild temperatures and wildflower blooms.

Overall, Colorado offers a wide range of attractions and activities for visitors to enjoy, making it a popular destination for travelers from around the world.