Started six years ago, the European map of indoor radon concentrations has evolved to includedata from 25 countries, covering a fair part of Europe. As of October 2012, the map is composed of morethan 18,000 non-empty grid cells with data, based on more than 800,000 individual measurements. Thenumber of measurements per cell ranges from one up to nearly 24,000. The coverage of territory varieswidely between the countries: from less than 20% for some up to more than 100% for others (due to aborder effect). While the arithmetic mean for all non-empty cells in Europe (for all participating countries) is 100 Bq/m³, the median is 65 Bq/m³. In parallel, a European map of geogenic radon potentialis under development, with a first, trial map having been published. These and other maps will eventuallyform parts of a planned European Atlas of Natural Radiation.