Monaco (French: Principauté de Monaco), is a sovereign city-state, country, and microstate on the French Riviera in Western Europe. France borders the country on three sides while the other side borders the Mediterranean Sea. Monaco is about 15 km (9.3 mi) from the state border with Italy.

Monaco has an area of 2.020 km2 (0.780 sq mi), making it the second-smallest country in the world after the Vatican. Its population as of 2018 is 38,682. With 19,009 inhabitants per square kilometre (49,230/sq mi), it is the most densely-populated sovereign state in the world. Monaco has a land border of 5.47 km (3.40 mi),[4] the world's shortest coastline of approximately 3.83 km (2.38 mi) (regardless of the coastline paradox), and a width that varies between 1,700 and 349 m (5,577 and 1,145 ft). The highest point in the country is a narrow pathway named Chemin des Révoires on the slopes of Mont Agel, in the Les Révoires Ward, which is 161 metres (528 feet) above sea level. Monaco's most populous Quartier is Monte Carlo and the most populous Ward is Larvotto/Bas Moulins. Through land reclamation, Monaco's land mass has expanded by 20 percent; in 2005, it had an area of only 1.974 km2 (0.762 sq mi). Monaco is known to be the most expensive and the wealthiest place on Earth, Vatican City excluded, due to its tax laws. In 2014, it was noted that about 30% of the population was made up of millionaires.