"Mathematics helps us to understand the world around us. Through this project students have had the opportunity to realize how mathematics can be applied in real life and how useful they are. Mathematical ideas were mixed with History, Arts, Cryptography and Computing Science. Students were asked to explore, analyse and draw their conclusions on issues of greatest cultural value, so that they improve their knowledge about European cultural heritage and Mathematics.The aim of the project was to involve our students in interdisciplinary activities that, through maths, model and describe real word and reinforce positive attitudes towards science. Students have cultivated communicative and exploratory skills, respect for the differences between European inhabitants. By using online communities, web 2.0 tools, specific mathematical software and mobile devices their digital skills have been improved.3 high schools from Spain, Greece and Romania have been the partners. Our common goals are to promote active learning, to increase students’ knowledge about the learning process in science, to apply several student-centred teaching methods, to innovate in teaching techniques and to improve the European dimension in our schools.Our objectives were:To learn how scientists investigate and become researchers themselves by designing and implementing a transnational survey.To apply cryptography and study European artistic heritage.To create algorithms connecting maths, cryptography, computer science and Arts for the objective above.To cultivate exploratory skills, reasoning and reflective thinking, creativity, imagination, self-assessment, autonomy.To reinforce positive attitude towards mathematics, by connecting them with the real world.To ""learn to co-exist"" by cultivating communicative skills, as well as respect for the perceptions, the values and the cultural characteristics of other European members.To avoid the ""digital divide"" and motivate our girls to engage in science.To “learn to act"", addressing different situations and experiencing formal and non-formal learning experiences in wider local or national environments.Τo manage, evaluate and produce digital collaborative material.To participate wisely and responsibly in online learning communities (e.g Twinspace).To interact with open dynamic software and web 2.0 tools.To use mobile devices as educational tools to connect Arts with science in different activities.In order to achieve those objectives, the project includes 4 main activities: statistics, geometry and Arts, cryptography and mathematical walks.In statistics, participants created a survey searching students’ perceptions about mathematics. Through a very important topic for the educational community, students discovered the importance of statistics in life.Students explored the contribution of maths to Arts, raising awareness of the importance of Europe's cultural heritage. Students made their own artistic constructions and with the cooperation of Laboratory Centre of School Science of Rethymno (Greece), they built a “camera obscura”, they also made constructions of tessellations and arcs with Geogebra and, as a consequence they made their own t-shirts with those designs.The third activity was about cryptography, students applied mathematical functions and identified the connection between maths and cryptography. They encrypted and deciphered texts about European monuments they have visited in the face to face meetings. In Twinspace, they created collaboratively algorithms like a coding/decoding machine .The fourth activity was the mathematical walk. Each country prepared a mathematical walk and upload it to website mathcitymap.eu app.Results:An infographic with the conclusions of the statistical surveyA magazine (https://madmagz.com/magazine/1731892) showing all our work.Three new items in the app mathcitymap.Twinspace (https://twinspace.etwinning.net/92568/home) with all the activities during and between the mobilities.Website https://mathsisaroundus.blogspot.com/ Students artistic constructions and a “camera obscura”A photo album showing the main points of the walks and the greatest moments of each visitLonger benefits: Participants will realize that education is not restricted to the borders of a country European dimension of education will be reinforced Basic skills and key competences will be cultivated Teachers will learn alternative and innovative methods of teaching Students reinforce their language skills and the mathematical skills School curriculum will be benefit due to the fact that activities can be integrated in school’s lessons of geometry, art, statistics, ICT. The magazine is available at school’s libraries and public libraries of our cities. New students at school will be able to enjoy the mathematical trails, they also will be able to use the spreadsheets to learn cryptography"