A must see in the neighbourhood, not really for the church itself but for the beautoful view over Paris. After you can walk down the rue Steinkerque and visit the Rue des Martyrs.
Well, I think I do not need to introduce you to one of Paris most well known places, Le Sacré Choeur. A remanbrance of when I was little : my mothers Godfather lived at the foot of the hill...great souvenirs! Please, be carefull with pick pockets
The gorgeous white basilica overlooking the city of Paris. My favorite time to go is early (around 7 or 8 am), before all the tourists arrive, and watch the city wake up.
'The' Sacré-Coeur. Walk up to it for a wide view of Paris, enjoy the gardens and Place du Tertre, then stroll down to Pigalle, Montmartre.