Earlier this month, San Francisco officially began construction on the Twin Peaks Promenade Project, one of the final stages of an ongoing effort to improve Twin Peaks as a public park and recreational area.
Twin Peaks Promenade Project

As a result, the Crestline Trail, which is the popular route to reach the western part of Twin Peaks on foot, will be closed for an estimated 9 months. While the popular trail will be closed, you can still access Christmas Tree Point via a reroute that leads north.
The project plans to turn the closed portion of Twin Peaks Boulevard into a linear park. The park will have two trails, one paved for bicycles and accessibility. Other amenities will include overlooks, seating, and more.
Twin Peaks has undergone many years of improvements starting in 2013. Many of the improvements focused on the trails around Twin Peaks, which are highly frequented by tourists and locals alike. While the Crestline Trail is closed, you can still visit the scenic park to take in the views, and look forward to the new addition in approximately 9 months.
About Twin Peaks
Twin Peaks is 922 feet tall, offering incredible views of San Francisco and the Bay. The 64-acre park is what many of SF’s hilltops looked like before construction, and many tourists and locals regularly venture to the peaks to take in the views. The park is located near the Castro and Noe Valley, and is frequented by skateboarders, bicyclists, and pedestrians. You can access the park by car, but many people opt to walk one of the scenic trails to the top.