Quantum computing requires the development of the quantum bits with a long coherence time and the ability to manipulate them in a fault tolerant manner.  Both goals can be achieved by the realization of a protected logical qubit formed by a collective state of an array of faulty qubits (see, e.g. [1]).  The building block (i.e. the faulty qubit) of the array is the Josephson element with an effective Josephson energy , which is p - periodic in the phase difference  across the element (the so-called Josephson rhombi).  Recently we made an essential step towards building a protected Josephson qubit by fabricating the simplest protected circuit and demonstrating that the low-energy quantum states of the circuit are protected from energy relaxation. The circuit contains two rhombi; novel design of these elements reduces their sensitivity to the offset charge asymmetry. We observed a ten-fold increase of the life time of the   state of this circuit due to the symmetry protection. The measured phase and charge dependences of the energies of the  transition are in good agreement with our numerical simulations. This demonstrates the capability of realization of protected structures with the existing fabrication methods and the potential of Josephson rhombi as the elements of protected qubits. The experiments provide a solid foundation for the next stage – the implementation of a qubit based on larger arrays of  elements where, according to the theoretical predictions, much improved coherence is expected.