Madrid is set to transform its northern entrance with a vast urban park, a 35-meter-high solar structure, and a 675-meter tunnel to divert traffic underground. The project promises more green space, improved mobility, and a bold new landmark for the capital.
Construction crews in Madrid have completed the excavation of a 675-meter tunnel beneath the Paseo de la Castellana, marking a decisive step toward the opening of the city's most ambitious urban park in years. The new Parque Castellana, spanning 70,000 square meters, is designed to reclaim public space from traffic and introduce a dramatic solar canopy that will become a defining feature of the northern cityscape.
At the heart of the project stands a 35-meter-tall elliptical solar pergola, already under installation at the park's northern edge. Weighing 33 tons and supporting 2,500 square meters of photovoltaic panels, the structure will generate up to 340 kW of clean energy—enough to power the tunnel's infrastructure and potentially feed surplus electricity back into the grid. According to Madrid City Council, this technological centerpiece will serve both as a visual landmark and a practical energy solution for the area.
Transforming Mobility
The new tunnel, stretching from Calle de Sinesio Delgado to the Nudo Norte interchange on the M-30, will reroute through-traffic underground, freeing the surface for local vehicles and public transport. With three lanes in each direction and dedicated access points, the tunnel is scheduled to open to traffic in December 2026. Above ground, the reclaimed space will be dedicated to pedestrians, cyclists, and green areas, fundamentally altering the flow and feel of one of Madrid's busiest corridors.
Plans also include a second underground level, to be excavated this summer, which will enable future connections to the Begoña neighborhood and the Madrid Nuevo Norte business district. This forward-looking design aims to integrate the park seamlessly with upcoming urban developments, ensuring long-term flexibility and connectivity.
Green Spaces and Community Life
Parque Castellana is set to become a new green axis linking the area of the five towers, Hospital Universitario La Paz, the historic San Cristóbal neighborhood, and the future Madrid Nuevo Norte hub. The landscaping plan calls for the planting of 772 new trees—bringing the total to over 1,000—alongside more than 38,800 shrubs, a pine grove with cypresses, cedars, and holm oaks, and a variety of recreational amenities.
Residents and visitors will find shaded seating areas, children's playgrounds, calisthenics equipment, a biosaludable circuit, and a segregated two-way bike lane along the eastern edge. The southern tip of the park will feature a landscaped hill, stone benches, an open-air amphitheater, a large fountain, and a central plaza shaded by a second, smaller pergola measuring 25 meters in diameter.
Energy and Urban Innovation
Beneath the main solar canopy, a dedicated pavilion will house the equipment needed to convert and manage the generated electricity, with the capacity to export excess power to the city's grid. The only transversal crossing in the park will be reserved for public transport and local traffic, ensuring smooth mobility while prioritizing green and communal spaces.
The €110.2 million investment reflects Madrid's commitment to sustainable urban transformation, combining infrastructure upgrades with environmental stewardship. As the city prepares for the tunnel's opening and the park's final landscaping phase, the project stands out as a model for integrating renewable energy and public space in dense urban environments.
Madrid's approach to large-scale urban renewal echoes the entrepreneurial spirit seen in other sectors, such as the fitness industry, where innovative investments have reshaped city life—much like the story of Vitalfit's expansion in Palma de Mallorca, detailed in this report on building a multi-million euro gym chain.
With excavation complete and the solar structure rising, Parque Castellana is poised to become a signature transformation for Madrid—reducing surface traffic, expanding green space, and setting a new standard for urban design in Spain's capital.
