Reims, an absolutely charming city, is East-Northeast of Paris, about 80 miles or 130 kilometers from Paris and easily reachable by train. It's one of the major cities in the Champagne region, and popular with tourists for its nightlife, history, and Champagne houses with impressive and enormous cellars built in Roman chalk mines dating back to 2000 years ago.
Sometimes spelled Rheims in English, it has a big city feel to it with lots of restaurants, bars, and other nightlife which is very unusual in this part of France. It is the largest city in Champagne with slightly under 200,000 residents in the city proper and almost 300,000 residents in the overall urban environment as measured by the 2008 Census. There is plenty of tourism in Reims.
It's an easy and fun place to visit as it has plenty to do and it is easy to get around without a car, in the center is very walkable, there are buses for going beyond the center. The center, the Place Drouet d'Erlon, is extremely pedestrian friendly and surrounded by bars, restaurants, and cafes. Place Drouet d'Erlon even looks a bit like an Art Deco Las Vegas at night. Ideal for a first time trip to Champagne, day trips from Paris are easy and fully guided day trips are also available.
Reims was founded in 80 BC and was the capitol of the tribe of the Remi. Various Popes hung out at times in Reims, including Pope Stephen II, Pope Leo III, and Pope Stephen IV, often with other famous historical figures like Charlemagne and Pepin The Short. There has been a lot of upheaval historically in Reims, including its capture by Julius Caesar, The Vandals, and even Attila the Hun. More recently the Germans have trashed it in World War I and II.
Perhaps the most beautiful building of the Middle Ages is in Reims. The Gothic Cathedrale Notre Dame, where Charles VII was coroneted (with Joan of Arc by his side) as well as most French Kings over the last millennium. It was heavily damaged in both World Wars and repaired through international support. The German's purposeful shelling of Notre Dame in WW I would qualify as a war crime today, although not back then.
Reims is one the centers of Champagne production and the most impressive Champagne Houses are in Reims as well. There are more in Epernay, but you just can't beat the cellars built out of 2000 year old Gallo-Roman chalk cellars. They are the most amazing anywhere, and even non Champagne drinkers should visit at least one if given a chance.
Just a few other things of interest include several museums, the Mars Gate ("Porte de Mars") a triumphal arch which is 108 feet long and 43 feet high from the 3rd or 4th century, the Palace of Tau, formerly the palace of the Archbishop of Reims and now a UNESCO World Heritage Site, the Saint Remi Basilica, many other interesting buildings, as well as a series of forts about 10 kilometers from the city center.
Reims, a charming city, with lots to see and do, but to me the biggest reason to visit has to do with that wonderful sparkling elixir known as Champagne!