Ok this metro is sketchy and I would only go to it because I was going to play soccer at Le Five (YES I KNOW IT'S FOOT IN FRANCE/THE EU - BUT I SAY SOCCER SO GET OVER IT). In general the station is kind of run down (although it doesn't smell too bad so 2 stars). There is not much to do in general in this area.
There are not any interesting bars or restaurants that I have identified in the vicinity and I am not too keen in spending the time there to find out. I don't go past Jules Joffrin much... Marx Dormoy if I really want some authentic Asian food and don't feel like going to the 13th arrondisement.
Porte de la Chapelle is at the edge of Paris an is a fairly uninteresting area with a lot of transport coming together (buses, trams, the metro, and the Périphérique highway). So you may end up here because you want to transfer to the tram or a bus...
Back to the metro, on a side note there is a group of homeless people who like to hang out in the metro stations between Pigalle and La Chapelle and get wasted/pee everywhere/intimidate metro riders/smoke cigarettes. Many of the stations are deep so it's warm and I can understand the allure - but they could be a little more courteous with their use of the public stations. That being said, some of them are very nice and deserve a smile and some change if you have it. But seriously, the peeing and smoking need to stop...
My recommendation is that the sooner you can get off of the 12 the better when you are heading north - especially in the evening hours. Plus the above ground walk up through Montmartre is one of the most beautiful stroles in Paris (but again watch your pockets in the Pigalle/Blanche area and around the Sacre Cœur and avoid the guys trying to make you a "friendship bracelets"...they are not your friends). read more