You owe yourself to walk from Ile de la Cité to Ile Saint-Louis if you're into romantic strolls and real Parisian mood. The two ilands are connected with the bridge Pont Saint-Louis and what it's lacking of historical touch (the current bridge was completed in 1970) is plenty made up with charm and soul.
The current bridge is the 7th to connect the two islands since 1630 and there's a wonderful view over the Seine and Paris when you stand on it. Since the bridge is closed for traffic it's inviting for romantic strolls and walking arm in arm. Both tourists and locals use this little gem of peace and romance in the middle of Paris.
That the cars are absent is an open invitation for street musicians and other street performers. You can always find at least one who plays music or performs when you cross the bridge. Take the time to enjoy the special mood which is only found in Paris by the Seine. It's certainly worth it.
I clearly remember the first romantic dinner I had in Paris at a charming little restaurant on Ile Saint-Louis. Afterwards we walked closely arm in arm towards the metro and crossed the bridge. It was a cool autumn evening and yet an older man sat there and played the accordian. The music was perfect for the evening and the romance, and it touched me so much that I got tears in my eyes. See, that's the real paris, don't cheat yourself from it.