Property Investment Hotspots in Spain. The hotspots in Spain are concentrated in Barcelona, Madrid and Valencia and along the Mediterranean coast. Spanish cities are expensive. The area around Valencia is a region that is tipped as an investment. The Costa del Sol is the Spanish coast which has attracted the majority of foreign investment over time. It has sandy beaches and year round sun. Costa del Sol property market is still growing and the prices continue to rise steadily. It’s a good place to invest for those with a large budget.