San Cristóbal de La Laguna (commonly known as La Laguna) is a city and municipality in the northern part of the island of Tenerife in the Province of Santa Cruz de Tenerife, on the Canary Islands (Spain). The city is third-most populous city of the archipelago and second-most populous city of the island. It is a suburban area of the city of Santa Cruz de Tenerife. La Laguna historical center was declared World Heritage Site by the UNESCO in 1999. Starting in 2003 the municipality started an ambitious Urban Plan to renew this area, that was carried out by the firm AUC S.L. (Arquitectura Urbanismo y Cooperación). The city was the ancient capital of the Canary Islands. La Laguna is physically part of the city of Santa Cruz, as both cities and municipalities, form a single large urban center, which is in the process of consolidating their union with other populations.