The capital and most populous city of France, Paris and best Things to do there has been one of the world's major centres of finance, diplomacy, commerce, fashion, gastronomy, science, and arts, and has sometimes been referred to as the capital of the world. The City of Paris is the centre and seat of government of the region and province of Île-de-France, or Paris Region, with an estimated population of 12,997,058 in 2020, or about 18% of the population of France, making it in 2020 the second largest metropolitan area in the OECD, and 14th largest in the world in 2015. The Paris Region had a GDP of €709 billion ($808 billion) in 2017. According to the Economist Intelligence Unit Worldwide Cost of Living Survey, in 2021 Paris was the city with the second-highest cost of living in the world, tied with Singapore, and after Tel Aviv.
Paris is a major railway, highway, and air-transport hub served by two international airports: Paris–Charles de Gaulle (the second-busiest airport in Europe) and Paris–Orly. Opened in 1900, the city's subway system, the Paris Métro, serves 5.23 million passengers daily; it is the second-busiest metro system in Europe after the Moscow Metro. Gare du Nord is the 24th-busiest railway station in the world and the busiest located outside Japan, with 262 million passengers in 2015. Paris is especially known for its museums and architectural landmarks: the Louvre received 2.8 million visitors in 2021, despite the long museum closings caused by the COVID-19 virus. The Musée d'Orsay, Musée Marmottan Monet and Musée de l'Orangerie are noted for their collections of French Impressionist art. The Pompidou Centre Musée National d'Art Moderne has the largest collection of modern and contemporary art in Europe. The Musée Rodin and Musée Picasso exhibit the works of two noted Parisians. The historical district along the Seine in the city centre has been classified as a UNESCO World Heritage Site since 1991; popular landmarks there include the Cathedral of Notre Dame de Paris on the Île de la Cité, now closed for renovation after the 15 April 2019 fire. Other popular tourist sites include the Gothic royal chapel of Sainte-Chapelle, also on the Île de la Cité; the Eiffel Tower, constructed for the Paris Universal Exposition of 1889; the Grand Palais and Petit Palais, built for the Paris Universal Exposition of 1900; the Arc de Triomphe on the Champs-Élysées, and the hill of Montmartre with its artistic history and its Basilica of Sacré-Coeur.
Paris hosts several United Nations organisations: the UNESCO, the Young Engineers / Future Leaders, the World Federation of Engineering Organizations, and other international organisations such as the OECD, the OECD Development Centre, the International Bureau of Weights and Measures, the International Energy Agency, the International Federation for Human Rights, the International Organisation of La Francophonie; along with European bodies such as the European Space Agency, the European Banking Authority or the European Securities and Markets Authority. Other international organisations were founded in Paris such as the CIMAC in 1951 (International Council on Combustion Engines | Conseil International des Machines à Combustion), or the modern Olympic Games in 1894 which was then moved to Lausanne, Switzerland.
Tourism recovered in the Paris region in 2021, increasing to 22.6 million visitors, thirty percent more than in 2020, but still well below 2019 levels. The number of visitors from the United States increased by 237 percent over 2020. Museums re-opened in 2021, with limitations on the number of visitors at a time and a requirement that visitors wear masks.
The football club Paris Saint-Germain and the rugby union club Stade Français are based in Paris. The 80,000-seat Stade de France, built for the 1998 FIFA World Cup, is located just north of Paris in the neighbouring commune of Saint-Denis. Paris hosts the annual French Open Grand Slam tennis tournament on the red clay of Roland Garros. The city hosted the Olympic Games in 1900, 1924 and will host the 2024 Summer Olympics. The 1938 and 1998 FIFA World Cups, the 2007 Rugby World Cup, as well as the 1960, 1984 and 2016 UEFA European Championships were also held in the city. Every July, the Tour de France bicycle race finishes on the Avenue des Champs-Élysées in Paris.

Widely recognised as one of the greatest mathematicians and physicists and among the most influential scientists of all time, Isaac Newton net worth who was an English mathematician, physicist, astronomer, alchemist, theologian, and author (described in his time as a "natural philosopher").He was a key figure in the philosophical revolution known as the Enlightenment. His book Philosophiæ Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), first published in 1687, established classical mechanics. Newton also made seminal contributions to optics, and shares credit with German mathematician Gottfried Wilhelm Leibniz for developing infinitesimal calculus.In the Principia, Newton formulated the laws of motion and universal gravitation that formed the dominant scientific viewpoint for centuries until it was superseded by the theory of relativity. Newton used his mathematical description of gravity to derive Kepler's laws of planetary motion, account for tides, the trajectories of comets, the precession of the equinoxes and other phenomena, eradicating doubt about the Solar System's heliocentricity. He demonstrated that the motion of objects on Earth and celestial bodies could be accounted for by the same principles. Newton's inference that the Earth is an oblate spheroid was later confirmed by the geodetic measurements of Maupertuis, La Condamine, and others, convincing most European scientists of the superiority of Newtonian mechanics over earlier systems.Newton built the first practical reflecting telescope and developed a sophisticated theory of colour based on the observation that a prism separates white light into the colours of the visible spectrum. His work on light was collected in his highly influential book Opticks, published in 1704. He also formulated an empirical law of cooling, made the first theoretical calculation of the speed of sound, and introduced the notion of a Newtonian fluid. In addition to his work on calculus, as a mathematician Newton contributed to the study of power series, generalised the binomial theorem to non-integer exponents, developed a method for approximating the roots of a function, and classified most of the cubic plane curves.Newton was a fellow of Trinity College and the second Lucasian Professor of Mathematics at the University of Cambridge. He was a devout but unorthodox Christian who privately rejected the doctrine of the Trinity. He refused to take holy orders in the Church of England, unlike most members of the Cambridge faculty of the day. Beyond his work on the mathematical sciences, Newton dedicated much of his time to the study of alchemy and biblical chronology, but most of his work in those areas remained unpublished until long after his death. Politically and personally tied to the Whig party, Newton served two brief terms as Member of Parliament for the University of Cambridge, in 1689–1690 and 1701–1702. He was knighted by Queen Anne in 1705 and spent the last three decades of his life in London, serving as Warden (1696–1699) and Master (1699–1727) of the Royal Mint, as well as president of the Royal Society (1703–1727).

Being the northernmost and westernmost of the 32 federal entities of Mexico, there are many things to do in Baja California. Before becoming a state in 1952, the area was known as the North Territory of Baja California (Territorio Norte de Baja California). It has an area of 70,113 km2 (27,071 sq mi) (3.57% of the land mass of Mexico) and comprises the northern half of the Baja California Peninsula, north of the 28th parallel, plus oceanic Guadalupe Island. The mainland portion of the state is bordered on the west by the Pacific Ocean; on the east by Sonora, the U.S. state of Arizona, and the Gulf of California; on the north by the U.S. state of California; and on the south by Baja California Sur.The state has an estimated population of 3,769,020 as of 2020, significantly higher than the sparsely populated Baja California Sur to the south, and similar to San Diego County, California, to its north. Over 75% of the population lives in Mexicali (the state's capital city), Ensenada, or Tijuana (the state's largest city). Other important cities include San Felipe, Rosarito, and Tecate. The population of the state is primarily composed of Mestizos, mostly migrants from other parts of Mexico, and as with most northern Mexican states, a large population of Mexicans of Spanish ancestry, and also a large minority group of people with East Asian, Middle Eastern, and indigenous descent. Additionally, there is a large immigrant population from the United States due to its proximity to San Diego and the significant lower cost of living compared to San Diego. There is also a significant population from Central America. Many immigrants moved to Baja California for a better quality of life and the number of higher-paying jobs in comparison to the rest of Mexico and Latin America.Baja California is the 12th-largest state by area in Mexico. Its geography ranges from beaches to forests and deserts. The backbone of the state is the Sierra de Baja California, where Picacho del Diablo, the highest point of the peninsula, is located. This mountain range effectively divides the weather patterns in the state. In the northwest, the weather is semi-dry and Mediterranean. In the narrow center, the weather changes to be more humid due to altitude. It is in this area where a few valleys can be found, such as the Valle de Guadalupe, the major wine-producing area in Mexico. To the east of the mountain range, the Sonoran Desert dominates the landscape. In the south, the weather becomes drier and gives way to the Vizcaíno Desert. The state is also home to numerous islands off both of its shores. Baja California is also home to Guadalupe Island, the westernmost point of Mexico. The Coronado Islands, Todos Santos islands, and Cedros Island are also on the Pacific shore. On the Gulf of California, the largest island is Angel de la Guarda Island, separated from the peninsula by the deep and narrow Canal de Ballenas.