"In the case of Spanish tourists, the least known destinations are Las Medulas or the Lagunas de Ruidera Natural Park."
In the final stage of the campaign, organized by travel insurance company Allianz Global Assistance, a team of "explorers" will be picked to officially inaugurate a new tourist route around the sites.
All travel expenses and a "salary" of €1,500 ($2,045) will be provided for each explorer to cover a two-week tour of all seven.
The website will be accepting applications from Spanish speakers until June 30.
The list of natural wonders includes: Gaztelugatxe, a small rocky island; Somiedo Natural Park, a mountain wildlife haven; Cabo de Gata-Nijar Natural Park, a volcanic landscape in southern Andalusia; Las Medulas, an ancient gold mine; Lagunas de Ruidera Natural Park, a landscape of lakes; Fuente De, a gorge in the Picos de Europa mountains and As Catedrais beach, a stunning spot on Spain's northern coast.