I read this in another forum
In Spain, until recently owners of property and assets had to pay wealth tax (impuesto sobre el patrimonio) on their assets (other than on their main home). If you were a resident of Spain you would be taxed on your WORLDWIDE assets. As a non-resident you would only be taxed on your assets held in Spain.
Therefore many of those who had become resident in Spain suddenly found that their assets in and outside Spain were taxable, with rates of 0.2% to 2.5% or more per annum depending on the value of the assets. ie: those who came out to live in Spain, and who owned other properties and assets were subject to tax on these assets as part of their net wealth (unless they could find a creative tax vehicle to hold the asset)
However, the good news for residents is that following the elections earlier this year, the Spanish Government has put in motion the abolishment of this tax, (as of Jan 2008), making Spain a more attractive place for residents to live and saving all residents a bundle of cash!!