Cities close to Paris

Cities would be Rouen in Normandy and Reims in the Champagne region,within two Hours.
Smaller towns would be Chartres that has a great Cathedral and Vernon with Monet's House and Gardens,less than two Hours by train.
Mike

Thanks Mike for your suggestion.

worth visiting for a day? Depends on one's interest doesn't it?

Just a few, for me

Lille, Flemish architecture and art museum
Amiens, cathedral and floating gardens,
Calais, Rodin's perhaps most moving piece of sculpture Burghers of Calais, fabulous pommes frites,
Arras, more Flemish architecture
Cambrai, Fabulous Art Deco built after almost complete destruction in a WWI tank battle, perhaps the only beguinage left in France

Versailles, Chartres, Chantilly, Fontainebleau are some that Ihave visited.

The answer to this question really depends on the amount of time you would be willing to spend on a train rather than the distance.

For example, if you were willing to spend 2 hours each way (I'm not, don't get me wrong, but some would and do), you could visit Lyon or even Bordeaux.

Dijon is 1:40, Strasbourg 1:45.

What's the radius from Paris you are considering? That also depends if you're on the TER or TGV train.

I would suggest these towns/cities: Amiens, Soissons, Cambrai, Meaux, Fontainebleau, Compiegne, Chateau-Thierry, Metz, Arras, Beauvais.

Brussels by Thalys can be a lovely day IMHO, about 2 hours away. No need to try to see everything. Do a walking tour of the Avenue Louise or Schaerbeek neighborhoods. Stop at Mary for a chocolate break.

Visit the Grand Place or check out the world class Museum of Musical Instruments. Have a moules-frites and Trappist ale. And catch an evening train “home” to Paris.