Mention the Costa Blanca and most people will have heard of it. The community of Valencia, to which the Costa Blanca belongs, has three of Spain's first-division football teams, is renowned for its popular fiestas, the home of the traditional paella and, of course, the Valencia orange. However, mention the fact that the region was also a retirement home for Nazis and someone, somewhere will be reaching for Godwin's law.

Over the last year in Spain, two books have been published that deal with the subject of Nazis who found refuge on the Costa Blanca. The first is Clara Sánchez's critically acclaimed bestseller and prize-winning novel, What Your Name Hides (Lo que esconde tu nombre), which tells the story of Sandra and Julian and their connection with a group of retired Nazis on the Costa Blanca.

Sandra, a young pregnant woman from Madrid, escapes to the coast to rethink her life and ends up forming a close relationship with an elderly couple. Julian, on the other hand, is an octogenarian survivor of the Mauthausen death camp and retired Nazi hunter who lives in Buenos Aires, but who comes to Spain in search of justice after receiving a tipoff about the location of a former high-ranking Nazi. Although the two narrators of the story are fictional, the location is not: Denia is a real city, which served as both a refuge and transit point for a number of prominent Nazis – some of whom are portrayed in Sanchez's novel.

The second book, The Footprint of the Boot (La huella de la bota), is the work of investigative journalist Joan Cantarero, who dedicates a complete chapter to the subject of Nazis who found refuge in that part of Spain. Cantarero's research exposes the close ties between Spain's legally established neo-Nazi and extreme-rightwing groups and key members of nazism who sought refuge in Spain and South America after the second world war. It details a historical continuum in the relationship between Nazis in Europe from the outbreak of the Spanish civil war, through the second world war, the cold war and the fall of the iron curtain to present day.

Cantarero insists that "Spain not only has for decades been a haven for Nazis, but it still is" and reinforces this point with reference to the 1989 homage to Hitler in Madrid, which was held on the centenary of his birth and which was attended by dozens of neo-Nazis, including Leon Degrelle. Spain was the only European country to allow such a tribute and this small band of monsters, frequently hiding behind a benign facade, could safely continue to spread their hate-filled supremacist ideology even in retirement.

So why did so many fleeing Nazis choose Spain? The level of co-operation between Spain and Germany is characterised by the 1939 agreement between General Martínez Anido and Heinrich Himmler, by which any German resident of Spain, suspected of not supporting the Nazi cause, could be detained and repatriated immediately, without any preliminary extradition appeal or trial.

Spain, although in theory a neutral country, supplied the Nazis with a large quantity of materials that were of vital importance to their war effort. Indeed, many of the Francoists, especially Falangists, were sympathetic to the tenets of nazism and helped various Nazi organisations in Spain both during the second world war (such as facilitating the activities of the giant Sofindus holding company) and post war (in helping to organise refugee ratlines).

In 1941, the Franco regime ordered provincial governors to draw up a list of Jews living in Spain. The census, which included the names, occupation details, ideologies and other personal data on 6,000 Jews, was according to Spain's El País "presumably given to Himmler".

One late July, many years ago, I was strolling with a friend in Denia, passing the numerous restaurants and bars brimming with happy holidaymakers from all over Europe, many of retirement age. My friend asked: "Do you ever think: 'I wonder what some of these people got up to during the war'?" Cantarero estimates that hundreds of high-ranking Nazis found refuge in Spain, not counting the Nazi refugees of lesser rank. Other sources mention the naturalisation of tens of thousands of former Nazis, but whether this is true or not, the fact that Spain had a safe haven programme for Nazi refugees is well documented.

A number of those who found refuge in Spain and South America were wanted in connection with horrendous, cold-blooded crimes against humanity. Not only did they get away with it, but were free to enjoy retirement without regrets or atonement, or the renunciation of their ideology.

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