Spending time in nature during childhood appears to have a positive effect on adults' environmental orientations and pro-environmental behaviours (Chawla & Cushing, 2007; Thompson, Aspinall & Montarzino, 2008). Recently attention has been paid to the importance of emotional affinity or connection with the natural environment predicting pro-environmental behaviour (Kals, Schumacher & Montada, 1999; Müller, Kals & Pansa, 2009). This affective bond appears to be created during childhood (Hinds & Sparks, 2008) and it is a predictor of environmental friendly practices (Cheng & Monroe, 2010). Several factors may influence children's environmental bond such as nature near home (Collado & Corraliza, 2011), parent's environmental values (Cheng & Monroe, 2010) or environmental education programs (Evans, Brauchle, Haq, Stecker, Wong & Shapiro, 2007). There is also some initial limited evidence that a summer camp spent in nature may strengthen this bond (Ernst & Theimer, 2011). We hypothesized that a stay in a summer camp in nature constitutes a package of factors that have been proven to be influential: most of all the long term direct exposure, usually combined with play and educational interaction with nature, approved of, if not explicitly stimulated by parent who sing up, and pay to send their children to a camp. The present study intends to assess the possible effects that stays in different natural vs. urban summer camps have on children's environmental orientation variables such as Emotional Affinity toward Nature (EAN) or children's ecological worldviews and how these variables might affect different types of children's pro-environmental actions like intentions to visit natural environments and to carry out pro-environmental behaviours. A sample formed by 390 children (mean age = 10.88; SD = 2.17) who attended different sleep over summer camps in Spain was used. Data were collected on the first and last day of the camps. The first (C1), second (C2) and third (C3) camps were placed in natural settings and the fourth camp (C4) was set in an urban area. C1 and C2 were summer camps in nature without environmental education (EE) activities and C3 was a summer camp in nature with EE. Our results show that spending time in natural camps increases children's EAN as well as children's ecological worldviews and willingness of carrying out different behaviours compared to children spending time in an urban camp. No differences were found between the natural camp with EE and those without them. Spending time in a natural camp was found to be a predictor of willingness to carry out pro-environmental behaviours, and this relation was mediated by EAN and ecological worldviews. These results can be useful for future interventions aimed at raising children's environmental attitudes and willingness of carrying out pro-environmental behaviours. And this may in the end lead to adults' improved attitudes, and more favourable environmental behaviour. This research has been carried out supported by the Spanish Ministry of Sciences and Innovation (PSI 2009-13422).