The only way to see any european city a mon avis is on foot and Paris is no exception. I spent a whole year walking from the Bois de Bologne to the Bois de Versailles and back again; from Montmartre to Montparnasse and beyond. If occasionally, I took my decrepit racing-green and rusted bike, it was when I had somewhere in particular to go but without a destination, by far the best way is to set off and see what happens...

I came out of my house and turned right...

I'm not going to tell you exactly where this peculiar besuited frenchman hangs out because his full power to freak and amaze comes from his element of surprise - wonder around the Marais for long enough and he'll jump out at you.

The point is that this odd next door neightbour of mine, as he clung to his tree in desperation rain or shine, inspired me to begin collecting images of random acts of street art. You can very quickly collect an impressive range of tags and defacements, subvertism and stickers in Paris. As many and varied as the city's cafes and bistros.

My choix de jour is the humourous Space Invader.

Imagine the graffiti artist in their obligatory hoodie (plus beret presumably), creeping out under the cover of darkness armed not with a spray-can and a template but broken kitchen tiles, ceramic cement and a knowledge of 80s computer graphic design.

And every one is different...

No sooner do you get an eye for the ambition of this artist, you begin to spot Space Invaders in the most inaccessable of locations and you begin to wonder what else he/she is responsible for...

My advice is to set aside a whole sunny day in comfortable shoes. Head for the steps of Notre Dame before the drones get there - pick up a croissant en route - and before you set off, pick out on the far southern side of the city, the monstrous black form of the Montparnasse tower (it looks a bit like a spare Eiffel Tower still in it's packaging.) Head for it... vaguely... with a propensity to diversion and distraction, coffee, art galleries and ludicrously dressed women in high heels and foul moods.

When you do eventually meander into the deadly reaches of Montparnasse, head straight for the top floor. This purpose-built gallery offers the most comprehensive view of the city (it even has a great view of the Eiffel Tower, which is more than the Eiffel Tower can offer!) Once you overcome the dizziness and approach the floor-to-ceiling glass windows, you can take advantage of the almost birdseye view and retrace on the map the day's Space Invaders patrol.

I have collected 48 tiled works of graffiti. See how many you can get!

POST SCRIPT.

I feel foolish.

Go to www.space-invaders.com and you'll discover not only are there 704 Space Invaders in Paris, but they have begun to attack cities all over the world, from Los Angeles to Tokyo.

I am going to collect animated chickens around south London instead.