The tight twisty nature and no room for error characteristics of the Monte Carlo streets means that one error likely means end of race and into the barriers. It's this that sets this race apart from the rest. 78 laps of pure concentration - Ayrton Senna famously likened it to driving through a tunnel for two hours, zoning in on the perfect racing line for all that time.
Monaco is special. It is the symbol of everything Formula 1 is about: beauty, glamour, precision and reward. They have overhauled their pits complex in recent years to be in line with any other leading motor circuit and their marshals are the best in the world. The same can definitely not be said about the Spanish Grand Prix circuit.