I highly recommend staying at Miguel Angel's attic in Seville! The place is cozy and located in a calm area of the city which is 15 minutes on foot to the city centre. The views are great and Miguel Angel is a great host who cares about making your stay great and providing anything you need.
Small warning for people who drive to Seville: there is no available free parking space near the premises, but rather on the other side of the river (around 10 minutes on foot if you have a suitcase on you), which is not ideal if it rains.