Alycia's apartment is right in the heart of Paris close to Le Marais, it's very easy to get to from Gard Du Nord, so perfect if you travel in via Eurostar.
It is on the 4th floor of a building with no lift, so if you are not good with stairs then this isn't for you, but otherwise its a great find; the space is good for a couple or 2 friends travelling together as there is also a comfy sofa bed (double). The apartment has a small but functional kitchen and a small bathroom with separate toilet - if you are a large person you may find the toilet too small, but for us it was OK.
In the apartment there are some nice amenities, a coffee machine with many pods available waits for you, plus there as also some fruit juice in the fridge and some biscuits and little cakes which was a lovely touch.
The streets around the apartment are full of great shops, cafes and bars and Les Halles is only a few minutes walk away if you like shopping. It's a nice 10-15 minute walk down to The Seine and so easy to get around as there are a couple of subway stations within a few minutes walk and also lots of bus lines.
We stayed for 4 nights and it was the perfect base for us to explore Paris.