My husband and I stayed here in 2009 over Easter break, and we really enjoyed our stay. It's not luxurious and it's not the greatest hotel ever, but it had several things going for it:
-Central and pretty safe location by Largo di Torre Argentina--lots of restaurants nearby and a very short walk to the Pantheon area especially
-Anonymous and quiet because it's down a side alley and a little bit removed from the touristy areas
-Basic, but clean.
-Very affordable for the proximity to the heart of the city
When you think of a European "pension" that's kind of what you're getting with Arenula. It's very old, but it covers all of your needs and it's comfortable. I think it loses stars from the main ratings sources because the reception is on the "first" floor (which in America is what we call the second floor) and as far as I remember there's not an elevator. It's also down an alley off the main street so it's not super accessible in that respect either. The rooms are also different sizes. My husband had a different room when we first arrived and it was a tiny room with a huge bathroom; we were then moved into a huge room with a tiny bathroom (like, barely room to swing a cat). Breakfast is nothing to write home about, but it's kind of standard European continental breakfast fare. Good home base. We'd stay here again. read more