A pop-up theatre designed to resemble a "Minecraft tree" will be located at the Marble Arch Mound, opening in April 2026 and operating until June 2028. The Westminster City Council's planning committee has unanimously approved the venue, which will temporarily house the Arts Theatre during its refurbishment. The theatre is designed for a lifespan of 20 years, with potential relocation after two years. Local support for the project is strong, although some councillors have expressed concerns about the building's green cladding. Historic England has reservations about the structure's impact on the Marble Arch's prominence. The theatre will feature an aluminium frame with recycled materials, a foyer, bar, and a stage at the western end, with shipping containers used for additional facilities. The Arts Theatre's last performance at its current location is scheduled for December 31.