Very central, on the Alfama side (slightly uphill) about 3min walk from Pca do Comercio. The cathedral is literally on the square and on the path up to Castelo de S Jorge. Metro access isn't the best (11min uphill from Rossio) but close access to bus stops and tram, in fact the 12 and 28 trams, both which are convenient for sight seeing, stop right outside on the square. I did indeed hear them drive by well into the night and before the sun, plus the people queuing for them, but for having a room that faced the square, I'd say I slept alright. It is a very lively nbhd, but the double locked door felt safe. staff was nice. I never had any inconvenience with the shared bathroom (there were 2 on the floor, not sure how many rooms shared them). One thing about the room that could improve is the availability of outlets as there is one where the spaceheater had to be plugged in, and another one that isn't easily reachable under the bed frame area for charging devices. Overall though, for the price, I would be back to stay again.