The ice rinks at Montparnasse and in front of the Hôtel de Ville hold over 1000 square meters of ice. As of the 2007-2008 season, there is an ice village for children at the Hôtel de Ville location, as well as a smaller rink for beginners and children. Best of all? Now there is sledding! Nothing like the sledding hill where I grew up, but for the middle of Paris, it can't be beat!
Skate rental is 5€.
If you're looking for an Olympic-sized rink, try the Patinoire de Boulogne-Billancourt

