Circuit de Monaco downhill again to a double right-hander called "Portier," named after region of Monaco, before heading into the famous tunnel, a unique feature of a Formula One circuit. (Until 2009 only one other circuit, Detroit in 1982–88, featured a tunnel, but the F1 series now includes racing at the Yas Marina Circuit in Abu Dhabi, which presents a shorter tunnel at the exit of the pit lane.) As well as the change of light making visibility poor, a car can lose 20–30% of its downforce due to the unique aerodynamic properties of the tunnel. The tunnel also presents a unique problem
Montjuïc circuit the circuit. Signalling the return of Formula One cars to Montjuïc, Emerson Fittipaldi (re-)appeared in his Lotus 72, and Marc Gené drove a contemporary Ferrari. Montjuïc circuit The Montjuïc circuit is a former street circuit located on the Montjuïc mountain in Barcelona, Catalonia, Spain. The circuit was also the venue for the Spanish motorcycle Grand Prix from 1950 to 1968, and then hosted the event on even-numbered years until 1976. The last Formula One Grand Prix held there in 1975, is notable for both a fatal crash that led to Formula One abandoning the venue and the only occasion to