Every year the fifth and sixth grade students do a school trip to the Cornellà Museum of Mathematics. First, we visit the exhibition on the first floor where there are mathematical games such as mirror games, puzzles and optical illusions. After the visit, we participate in a quest (similar to a treasure hunt) outside, at Can Mercader Park. We solve mathematical problems following clues on a map. Each correct answer give us a letter and with these letters in the correct order we could form three mathematical questions. The result give us the numbers of the combination to open a mysterious box.The sixth group do a different activity. They work on the construction of Leonardo's domes using different geometric shapes.Ainara Romero García