Eight years ago, our school in Mexico was introduced to Logo as part of the governmentsponsored Teaching Mathematics with Technology (EMAT) program. Since then we have increasingly become interested in developing long-term, interesting, constructionist (Harel & Papert, 1991) projects for our students, particularly in the last 5 years. The idea is that through these projects students become engaged and motivated, while they learn – in a fun and meaningful way – many mathematical topics in the official syllabus, but also have early access to other “powerful ideas” (Papert, 1980) such as “advanced” mathematical concepts that are usually not even considered for children of the age-groups we work with (12-14 years-old), as is the case of trigonometry. At Eurologo 2007, we reported our first long-term “Painless trigonometry” project (Jiménez-Molotla et al., 2007). Our latest project, the “Paris project”, inspired by the hosting city for Constructionism 2010, evolved from that previous trigonometry project, and had as aim the construction of the Eiffel tower. Such construction, done in 3D MSWLogo, has required an understanding and use of trigonometric ideas, such as the Pythagorean theorem, and mathematical analyses using various tools (including Google Sketchup and Scratch) of geometrical objects such as pyramids and prisms, which form the building blocks of the Eiffel tower representation. As in our previous projects, the children have been highly motivated and engaged, and their creativity and genius has been awakened.