The urban development of the Lezkairu and Arrosadia areas has been the most important public works project in Pamplona.

The works were completed in 2013 and cost 120 million euros.

Lezkairu is located to the south of the II Ensanche and to the east of the Public University, while Arrosadia is located to the south of the La Milagrosa district and to the west of the Public University.

The total surface area is 112 hectares, of which 10 hectares are for public use (educational, cultural and sports facilities). The surface area of Lezkairu is 86 ha, with 5,800 dwellings planned, and that of Arrosadía is 25 ha, with 1,500 dwellings planned.  The configuration of the plots is orthogonal, replicating the II Ensanche.

It consists of 15 km of roads. Traffic is concentrated on the perimeter roads (the main routes are Juan Pablo II and Cataluña), with the interior roads being for pedestrian and vehicle coexistence. There are also 2 km of bicycle lanes. Several structures have been built, including the Mendillorri access bridge (60 m span in three sections), the bridge over the river Sadar in Avda. de Zaragoza (double bridge with a 20 m span) and the three structures of the raised roundabout in the Gran Plaza.

There are 25 ha of parks and gardens, including the Parque Norte (8 ha), the Parque Central (4 ha) and the Parque del Sadar in Arrosadía (3 ha) where a 4,000 m² lake has been designed with a geyser.

In terms of services and facilities, it is worth highlighting the uniqueness of this development, as all services (mains supply, drainage, electricity, telecommunications, lighting and pneumatic waste collection, with the exception of gas and the rainwater network, as required by regulations) run through a service tunnel, which has a total length of 7 km. The connections to the buildings are made through mini-pipelines (2 km).  Solid waste is collected through a pneumatic network that also runs through the service tunnel. The network has a length of 8 km, and the connections go up to all the levels of the buildings.

Complementary works include the redevelopment of the old quarter of Soto de Lezkairu, with 100 dwellings, and the construction of a 12 metre high panoramic lift giving access to Calle Monjardín street to the north of the development.