This paper presents the original pantomime-based training on Object Oriented Analysis/Objected Oriented Design (OOA/OOD) with Unified Modeling Language (UML). The essence of this training involves giving an assignment to create a high-level design for a software system to a team of students. They are required to use UML and are not allowed to use any other language (English, German, Russian, Ukrainian, etc), either spoken or written. Students are given 4-6 hours to complete the task. This assignment is always presented as an experiment - the students are to discover whether or not UML is "a real language" that can successfully serve as a communication tool within a team. The authors call this training "The Babel Experiment". This training allows students to work through typical problems of software development projects and to see how UML helps solve these problems. This training was developed by Vladimir L. Pavlov in 2001 and it has been successfully conducted at universities and software companies over ten times. In universities, this training has been used as a kind of capstone project for traditional OOA/OOD/UML courses; however, for software companies this training was mostly delivered as a stand-alone course. In all cases this training course has received very positive feedback from students and customers.