Le Portier & Mareterra: Monaco's New Eco-District

Monaco's newest quarter

Le Portier, officially named Mareterra, is Monaco's most ambitious urban project in decades: a six-hectare land extension built into the Mediterranean Sea between the Larvotto beach and the Grimaldi Forum. The project adds a new neighbourhood to a country that measures just over two square kilometres, providing residential space, public gardens, shops, and a redesigned coastline.

Construction began in 2017 with the creation of a massive concrete caisson infrastructure sunk into the seabed. The project was developed by SAM l'Anse du Portier under the authority of the Government of Monaco, with architectural direction from Renzo Piano, Daniel Libeskind, and other internationally recognised architects.

What Mareterra includes

Residential buildings

Mareterra features a small number of luxury residential buildings designed by different architects, each with distinct architectural character. The residences are intended to complement Monaco's existing housing stock at the highest end of the market. Apartments offer sea views and direct access to the new public promenades.

Public spaces and gardens

A significant portion of Mareterra is devoted to public use:

• A landscaped promenade along the waterfront, extending the existing coastal walkway
• Public gardens with Mediterranean planting, pedestrian paths, and seating areas
• A new marina with berths for mid-sized yachts
• Retail and dining spaces at ground level within the development

The public areas are open to all residents and visitors of Monaco, not restricted to building occupants.

The hill and park

The design includes an artificial hill planted with mature trees and vegetation, creating a green transition between the new buildings and the sea. This landscaped area is conceived as a public park, adding rare green space to the Principality.

Sustainability and environmental approach

Le Portier was designed as an eco-district from the outset. Key environmental features include:

• Marine biodiversity programme: artificial reef structures were installed around the perimeter of the extension to encourage marine life colonisation. Monitoring by the Centre Scientifique de Monaco tracks the ecological impact.
• Energy efficiency: buildings incorporate high insulation standards, seawater-based heating and cooling systems (thalassothermy), and photovoltaic panels.
• Waste management: integrated waste collection systems built into the infrastructure.
• Stormwater management: systems designed to prevent runoff from reaching the sea untreated.

The project has attracted both praise for its environmental ambition and scrutiny over the broader impact of building on the sea. Monaco's government has published environmental monitoring reports through the project's development.

Location and access

Mareterra sits along Avenue Princesse Grace, between the eastern end of Larvotto beach and the Grimaldi Forum. It is accessible on foot from the Larvotto promenade and by bus via the existing CAM routes serving the Larvotto and La Rousse areas.

The new promenade connects seamlessly with the existing coastal walk, extending the pedestrian route along Monaco's eastern waterfront.

Current status

The main infrastructure and buildings have been completed. Landscaping, public space finishings, and the opening of retail and hospitality venues are in various stages of completion. Mareterra is progressively integrating into Monaco's urban fabric.

For the latest updates on public access and openings, check the official Government of Monaco communications.

What Mareterra means for visitors

For visitors, Mareterra adds a new waterfront promenade, public gardens, and eventually new restaurants and shops to explore. The extension meaningfully expands Monaco's walkable coastline and provides a contemporary architectural contrast to the historic quarters. It is worth a visit for anyone interested in urban development, architecture, or simply a pleasant walk by the sea.