Modular system for gazebos, greenhouses and similar structures for outdoor or garden use provided with at least two side modules (2) which can be coupled together, and a roof (4) consisting of at least two roof modules (5). Each roof module (5) is provided with an interconnection system (13) for fixing each roof module (5), at the same time allowing it to be removed and rotated, to a side module (2). <IMAGE>
